# sql/compiler.py # Copyright (C) 2005-2021 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """Base SQL and DDL compiler implementations. Classes provided include: :class:`.compiler.SQLCompiler` - renders SQL strings :class:`.compiler.DDLCompiler` - renders DDL (data definition language) strings :class:`.compiler.GenericTypeCompiler` - renders type specification strings. To generate user-defined SQL strings, see :doc:`/ext/compiler`. """ import contextlib import itertools import re from . import crud from . import elements from . import functions from . import operators from . import schema from . import selectable from . import sqltypes from . import visitors from .. import exc from .. import util RESERVED_WORDS = set( [ "all", "analyse", "analyze", "and", "any", "array", "as", "asc", "asymmetric", "authorization", "between", "binary", "both", "case", "cast", "check", "collate", "column", "constraint", "create", "cross", "current_date", "current_role", "current_time", "current_timestamp", "current_user", "default", "deferrable", "desc", "distinct", "do", "else", "end", "except", "false", "for", "foreign", "freeze", "from", "full", "grant", "group", "having", "ilike", "in", "initially", "inner", "intersect", "into", "is", "isnull", "join", "leading", "left", "like", "limit", "localtime", "localtimestamp", "natural", "new", "not", "notnull", "null", "off", "offset", "old", "on", "only", "or", "order", "outer", "overlaps", "placing", "primary", "references", "right", "select", "session_user", "set", "similar", "some", "symmetric", "table", "then", "to", "trailing", "true", "union", "unique", "user", "using", "verbose", "when", "where", ] ) LEGAL_CHARACTERS = re.compile(r"^[A-Z0-9_$]+$", re.I) LEGAL_CHARACTERS_PLUS_SPACE = re.compile(r"^[A-Z0-9_ $]+$", re.I) ILLEGAL_INITIAL_CHARACTERS = {str(x) for x in range(0, 10)}.union(["$"]) FK_ON_DELETE = re.compile( r"^(?:RESTRICT|CASCADE|SET NULL|NO ACTION|SET DEFAULT)$", re.I ) FK_ON_UPDATE = re.compile( r"^(?:RESTRICT|CASCADE|SET NULL|NO ACTION|SET DEFAULT)$", re.I ) FK_INITIALLY = re.compile(r"^(?:DEFERRED|IMMEDIATE)$", re.I) BIND_PARAMS = re.compile(r"(?<![:\w\$\x5c]):([\w\$]+)(?![:\w\$])", re.UNICODE) BIND_PARAMS_ESC = re.compile(r"\x5c(:[\w\$]*)(?![:\w\$])", re.UNICODE) BIND_TEMPLATES = { "pyformat": "%%(%(name)s)s", "qmark": "?", "format": "%%s", "numeric": ":[_POSITION]", "named": ":%(name)s", } OPERATORS = { # binary operators.and_: " AND ", operators.or_: " OR ", operators.add: " + ", operators.mul: " * ", operators.sub: " - ", operators.div: " / ", operators.mod: " % ", operators.truediv: " / ", operators.neg: "-", operators.lt: " < ", operators.le: " <= ", operators.ne: " != ", operators.gt: " > ", operators.ge: " >= ", operators.eq: " = ", operators.is_distinct_from: " IS DISTINCT FROM ", operators.isnot_distinct_from: " IS NOT DISTINCT FROM ", operators.concat_op: " || ", operators.match_op: " MATCH ", operators.notmatch_op: " NOT MATCH ", operators.in_op: " IN ", operators.notin_op: " NOT IN ", operators.comma_op: ", ", operators.from_: " FROM ", operators.as_: " AS ", operators.is_: " IS ", operators.isnot: " IS NOT ", operators.collate: " COLLATE ", # unary operators.exists: "EXISTS ", operators.distinct_op: "DISTINCT ", operators.inv: "NOT ", operators.any_op: "ANY ", operators.all_op: "ALL ", # modifiers operators.desc_op: " DESC", operators.asc_op: " ASC", operators.nullsfirst_op: " NULLS FIRST", operators.nullslast_op: " NULLS LAST", } FUNCTIONS = { functions.coalesce: "coalesce", functions.current_date: "CURRENT_DATE", functions.current_time: "CURRENT_TIME", functions.current_timestamp: "CURRENT_TIMESTAMP", functions.current_user: "CURRENT_USER", functions.localtime: "LOCALTIME", functions.localtimestamp: "LOCALTIMESTAMP", functions.random: "random", functions.sysdate: "sysdate", functions.session_user: "SESSION_USER", functions.user: "USER", functions.cube: "CUBE", functions.rollup: "ROLLUP", functions.grouping_sets: "GROUPING SETS", } EXTRACT_MAP = { "month": "month", "day": "day", "year": "year", "second": "second", "hour": "hour", "doy": "doy", "minute": "minute", "quarter": "quarter", "dow": "dow", "week": "week", "epoch": "epoch", "milliseconds": "milliseconds", "microseconds": "microseconds", "timezone_hour": "timezone_hour", "timezone_minute": "timezone_minute", } COMPOUND_KEYWORDS = { selectable.CompoundSelect.UNION: "UNION", selectable.CompoundSelect.UNION_ALL: "UNION ALL", selectable.CompoundSelect.EXCEPT: "EXCEPT", selectable.CompoundSelect.EXCEPT_ALL: "EXCEPT ALL", selectable.CompoundSelect.INTERSECT: "INTERSECT", selectable.CompoundSelect.INTERSECT_ALL: "INTERSECT ALL", } class Compiled(object): """Represent a compiled SQL or DDL expression. The ``__str__`` method of the ``Compiled`` object should produce the actual text of the statement. ``Compiled`` objects are specific to their underlying database dialect, and also may or may not be specific to the columns referenced within a particular set of bind parameters. In no case should the ``Compiled`` object be dependent on the actual values of those bind parameters, even though it may reference those values as defaults. """ _cached_metadata = None schema_translate_map = None execution_options = util.immutabledict() """ Execution options propagated from the statement. In some cases, sub-elements of the statement can modify these. """ def __init__( self, dialect, statement, bind=None, schema_translate_map=None, compile_kwargs=util.immutabledict(), ): """Construct a new :class:`.Compiled` object. :param dialect: :class:`.Dialect` to compile against. :param statement: :class:`_expression.ClauseElement` to be compiled. :param bind: Optional Engine or Connection to compile this statement against. :param schema_translate_map: dictionary of schema names to be translated when forming the resultant SQL .. versionadded:: 1.1 .. seealso:: :ref:`schema_translating` :param compile_kwargs: additional kwargs that will be passed to the initial call to :meth:`.Compiled.process`. """ self.dialect = dialect self.bind = bind self.preparer = self.dialect.identifier_preparer self.schema_translate_map = schema_translate_map if schema_translate_map: self.preparer = self.preparer._with_schema_translate( schema_translate_map ) if statement is not None: self.statement = statement self.can_execute = statement.supports_execution if self.can_execute: self.execution_options = statement._execution_options self.string = self.process(self.statement, **compile_kwargs) @util.deprecated( "0.7", "The :meth:`.Compiled.compile` method is deprecated and will be " "removed in a future release. The :class:`.Compiled` object " "now runs its compilation within the constructor, and this method " "does nothing.", ) def compile(self): """Produce the internal string representation of this element.""" pass def _execute_on_connection(self, connection, multiparams, params): if self.can_execute: return connection._execute_compiled(self, multiparams, params) else: raise exc.ObjectNotExecutableError(self.statement) @property def sql_compiler(self): """Return a Compiled that is capable of processing SQL expressions. If this compiler is one, it would likely just return 'self'. """ raise NotImplementedError() def process(self, obj, **kwargs): return obj._compiler_dispatch(self, **kwargs) def __str__(self): """Return the string text of the generated SQL or DDL.""" return self.string or "" def construct_params(self, params=None): """Return the bind params for this compiled object. :param params: a dict of string/object pairs whose values will override bind values compiled in to the statement. """ raise NotImplementedError() @property def params(self): """Return the bind params for this compiled object.""" return self.construct_params() def execute(self, *multiparams, **params): """Execute this compiled object.""" e = self.bind if e is None: raise exc.UnboundExecutionError( "This Compiled object is not bound to any Engine " "or Connection.", code="2afi", ) return e._execute_compiled(self, multiparams, params) def scalar(self, *multiparams, **params): """Execute this compiled object and return the result's scalar value.""" return self.execute(*multiparams, **params).scalar() class TypeCompiler(util.with_metaclass(util.EnsureKWArgType, object)): """Produces DDL specification for TypeEngine objects.""" ensure_kwarg = r"visit_\w+" def __init__(self, dialect): self.dialect = dialect def process(self, type_, **kw): return type_._compiler_dispatch(self, **kw) class _CompileLabel(visitors.Visitable): """lightweight label object which acts as an expression.Label.""" __visit_name__ = "label" __slots__ = "element", "name" def __init__(self, col, name, alt_names=()): self.element = col self.name = name self._alt_names = (col,) + alt_names @property def proxy_set(self): return self.element.proxy_set @property def type(self): return self.element.type def self_group(self, **kw): return self class prefix_anon_map(dict): """A map that creates new keys for missing key access. Considers keys of the form "<ident> <name>" to produce new symbols "<name>_<index>", where "index" is an incrementing integer corresponding to <name>. Inlines the approach taken by :class:`sqlalchemy.util.PopulateDict` which is otherwise usually used for this type of operation. """ def __missing__(self, key): (ident, derived) = key.split(" ", 1) anonymous_counter = self.get(derived, 1) self[derived] = anonymous_counter + 1 value = derived + "_" + str(anonymous_counter) self[key] = value return value class SQLCompiler(Compiled): """Default implementation of :class:`.Compiled`. Compiles :class:`_expression.ClauseElement` objects into SQL strings. """ extract_map = EXTRACT_MAP compound_keywords = COMPOUND_KEYWORDS isdelete = isinsert = isupdate = False """class-level defaults which can be set at the instance level to define if this Compiled instance represents INSERT/UPDATE/DELETE """ isplaintext = False returning = None """holds the "returning" collection of columns if the statement is CRUD and defines returning columns either implicitly or explicitly """ returning_precedes_values = False """set to True classwide to generate RETURNING clauses before the VALUES or WHERE clause (i.e. MSSQL) """ render_table_with_column_in_update_from = False """set to True classwide to indicate the SET clause in a multi-table UPDATE statement should qualify columns with the table name (i.e. MySQL only) """ contains_expanding_parameters = False """True if we've encountered bindparam(..., expanding=True). These need to be converted before execution time against the string statement. """ ansi_bind_rules = False """SQL 92 doesn't allow bind parameters to be used in the columns clause of a SELECT, nor does it allow ambiguous expressions like "? = ?". A compiler subclass can set this flag to False if the target driver/DB enforces this """ _textual_ordered_columns = False """tell the result object that the column names as rendered are important, but they are also "ordered" vs. what is in the compiled object here. """ _ordered_columns = True """ if False, means we can't be sure the list of entries in _result_columns is actually the rendered order. Usually True unless using an unordered TextAsFrom. """ _numeric_binds = False """ True if paramstyle is "numeric". This paramstyle is trickier than all the others. """ insert_single_values_expr = None """When an INSERT is compiled with a single set of parameters inside a VALUES expression, the string is assigned here, where it can be used for insert batching schemes to rewrite the VALUES expression. .. versionadded:: 1.3.8 """ insert_prefetch = update_prefetch = () def __init__( self, dialect, statement, column_keys=None, inline=False, **kwargs ): """Construct a new :class:`.SQLCompiler` object. :param dialect: :class:`.Dialect` to be used :param statement: :class:`_expression.ClauseElement` to be compiled :param column_keys: a list of column names to be compiled into an INSERT or UPDATE statement. :param inline: whether to generate INSERT statements as "inline", e.g. not formatted to return any generated defaults :param kwargs: additional keyword arguments to be consumed by the superclass. """ self.column_keys = column_keys # compile INSERT/UPDATE defaults/sequences inlined (no pre- # execute) self.inline = inline or getattr(statement, "inline", False) # a dictionary of bind parameter keys to BindParameter # instances. self.binds = {} # a dictionary of BindParameter instances to "compiled" names # that are actually present in the generated SQL self.bind_names = util.column_dict() # stack which keeps track of nested SELECT statements self.stack = [] # relates label names in the final SQL to a tuple of local # column/label name, ColumnElement object (if any) and # TypeEngine. ResultProxy uses this for type processing and # column targeting self._result_columns = [] # true if the paramstyle is positional self.positional = dialect.positional if self.positional: self.positiontup = [] self._numeric_binds = dialect.paramstyle == "numeric" self.bindtemplate = BIND_TEMPLATES[dialect.paramstyle] self.ctes = None self.label_length = ( dialect.label_length or dialect.max_identifier_length ) # a map which tracks "anonymous" identifiers that are created on # the fly here self.anon_map = prefix_anon_map() # a map which tracks "truncated" names based on # dialect.label_length or dialect.max_identifier_length self.truncated_names = {} Compiled.__init__(self, dialect, statement, **kwargs) if ( self.isinsert or self.isupdate or self.isdelete ) and statement._returning: self.returning = statement._returning if self.positional and self._numeric_binds: self._apply_numbered_params() @property def current_executable(self): """Return the current 'executable' that is being compiled. This is currently the :class:`_sql.Select`, :class:`_sql.Insert`, :class:`_sql.Update`, :class:`_sql.Delete`, :class:`_sql.CompoundSelect` object that is being compiled. Specifically it's assigned to the ``self.stack`` list of elements. When a statement like the above is being compiled, it normally is also assigned to the ``.statement`` attribute of the :class:`_sql.Compiler` object. However, all SQL constructs are ultimately nestable, and this attribute should never be consulted by a ``visit_`` method, as it is not guaranteed to be assigned nor guaranteed to correspond to the current statement being compiled. .. versionadded:: 1.3.21 For compatibility with previous versions, use the following recipe:: statement = getattr(self, "current_executable", False) if statement is False: statement = self.stack[-1]["selectable"] For versions 1.4 and above, ensure only .current_executable is used; the format of "self.stack" may change. """ try: return self.stack[-1]["selectable"] except IndexError as ie: util.raise_( IndexError("Compiler does not have a stack entry"), replace_context=ie, ) @property def prefetch(self): return list(self.insert_prefetch + self.update_prefetch) @util.memoized_instancemethod def _init_cte_state(self): """Initialize collections related to CTEs only if a CTE is located, to save on the overhead of these collections otherwise. """ # collect CTEs to tack on top of a SELECT self.ctes = util.OrderedDict() self.ctes_by_name = {} self.ctes_recursive = False if self.positional: self.cte_positional = {} @contextlib.contextmanager def _nested_result(self): """special API to support the use case of 'nested result sets'""" result_columns, ordered_columns = ( self._result_columns, self._ordered_columns, ) self._result_columns, self._ordered_columns = [], False try: if self.stack: entry = self.stack[-1] entry["need_result_map_for_nested"] = True else: entry = None yield self._result_columns, self._ordered_columns finally: if entry: entry.pop("need_result_map_for_nested") self._result_columns, self._ordered_columns = ( result_columns, ordered_columns, ) def _apply_numbered_params(self): poscount = itertools.count(1) self.string = re.sub( r"\[_POSITION\]", lambda m: str(util.next(poscount)), self.string ) @util.memoized_property def _bind_processors(self): return dict( (key, value) for key, value in ( ( self.bind_names[bindparam], bindparam.type._cached_bind_processor(self.dialect), ) for bindparam in self.bind_names ) if value is not None ) def is_subquery(self): return len(self.stack) > 1 @property def sql_compiler(self): return self def construct_params(self, params=None, _group_number=None, _check=True): """return a dictionary of bind parameter keys and values""" if params: pd = {} for bindparam in self.bind_names: name = self.bind_names[bindparam] if bindparam.key in params: pd[name] = params[bindparam.key] elif name in params: pd[name] = params[name] elif _check and bindparam.required: if _group_number: raise exc.InvalidRequestError( "A value is required for bind parameter %r, " "in parameter group %d" % (bindparam.key, _group_number), code="cd3x", ) else: raise exc.InvalidRequestError( "A value is required for bind parameter %r" % bindparam.key, code="cd3x", ) elif bindparam.callable: pd[name] = bindparam.effective_value else: pd[name] = bindparam.value return pd else: pd = {} for bindparam in self.bind_names: if _check and bindparam.required: if _group_number: raise exc.InvalidRequestError( "A value is required for bind parameter %r, " "in parameter group %d" % (bindparam.key, _group_number), code="cd3x", ) else: raise exc.InvalidRequestError( "A value is required for bind parameter %r" % bindparam.key, code="cd3x", ) if bindparam.callable: pd[self.bind_names[bindparam]] = bindparam.effective_value else: pd[self.bind_names[bindparam]] = bindparam.value return pd @property def params(self): """Return the bind param dictionary embedded into this compiled object, for those values that are present.""" return self.construct_params(_check=False) @util.dependencies("sqlalchemy.engine.result") def _create_result_map(self, result): """utility method used for unit tests only.""" return result.ResultMetaData._create_result_map(self._result_columns) def default_from(self): """Called when a SELECT statement has no froms, and no FROM clause is to be appended. Gives Oracle a chance to tack on a ``FROM DUAL`` to the string output. """ return "" def visit_grouping(self, grouping, asfrom=False, **kwargs): return "(" + grouping.element._compiler_dispatch(self, **kwargs) + ")" def visit_label_reference( self, element, within_columns_clause=False, **kwargs ): if self.stack and self.dialect.supports_simple_order_by_label: selectable = self.stack[-1]["selectable"] with_cols, only_froms, only_cols = selectable._label_resolve_dict if within_columns_clause: resolve_dict = only_froms else: resolve_dict = only_cols # this can be None in the case that a _label_reference() # were subject to a replacement operation, in which case # the replacement of the Label element may have changed # to something else like a ColumnClause expression. order_by_elem = element.element._order_by_label_element if ( order_by_elem is not None and order_by_elem.name in resolve_dict and order_by_elem.shares_lineage( resolve_dict[order_by_elem.name] ) ): kwargs[ "render_label_as_label" ] = element.element._order_by_label_element return self.process( element.element, within_columns_clause=within_columns_clause, **kwargs ) def visit_textual_label_reference( self, element, within_columns_clause=False, **kwargs ): if not self.stack: # compiling the element outside of the context of a SELECT return self.process(element._text_clause) selectable = self.stack[-1]["selectable"] with_cols, only_froms, only_cols = selectable._label_resolve_dict try: if within_columns_clause: col = only_froms[element.element] else: col = with_cols[element.element] except KeyError as ke: elements._no_text_coercion( element.element, exc.CompileError, "Can't resolve label reference for ORDER BY / " "GROUP BY / DISTINCT etc.", err=ke, ) else: kwargs["render_label_as_label"] = col return self.process( col, within_columns_clause=within_columns_clause, **kwargs ) def visit_label( self, label, add_to_result_map=None, within_label_clause=False, within_columns_clause=False, render_label_as_label=None, **kw ): # only render labels within the columns clause # or ORDER BY clause of a select. dialect-specific compilers # can modify this behavior. render_label_with_as = ( within_columns_clause and not within_label_clause ) render_label_only = render_label_as_label is label if render_label_only or render_label_with_as: if isinstance(label.name, elements._truncated_label): labelname = self._truncated_identifier("colident", label.name) else: labelname = label.name if render_label_with_as: if add_to_result_map is not None: add_to_result_map( labelname, label.name, (label, labelname) + label._alt_names, label.type, ) return ( label.element._compiler_dispatch( self, within_columns_clause=True, within_label_clause=True, **kw ) + OPERATORS[operators.as_] + self.preparer.format_label(label, labelname) ) elif render_label_only: return self.preparer.format_label(label, labelname) else: return label.element._compiler_dispatch( self, within_columns_clause=False, **kw ) def _fallback_column_name(self, column): raise exc.CompileError( "Cannot compile Column object until " "its 'name' is assigned." ) def visit_column( self, column, add_to_result_map=None, include_table=True, **kwargs ): name = orig_name = column.name if name is None: name = self._fallback_column_name(column) is_literal = column.is_literal if not is_literal and isinstance(name, elements._truncated_label): name = self._truncated_identifier("colident", name) if add_to_result_map is not None: add_to_result_map( name, orig_name, (column, name, column.key), column.type ) if is_literal: # note we are not currently accommodating for # literal_column(quoted_name('ident', True)) here name = self.escape_literal_column(name) else: name = self.preparer.quote(name) table = column.table if table is None or not include_table or not table.named_with_column: return name else: effective_schema = self.preparer.schema_for_object(table) if effective_schema: schema_prefix = ( self.preparer.quote_schema(effective_schema) + "." ) else: schema_prefix = "" tablename = table.name if isinstance(tablename, elements._truncated_label): tablename = self._truncated_identifier("alias", tablename) return schema_prefix + self.preparer.quote(tablename) + "." + name def visit_collation(self, element, **kw): return self.preparer.format_collation(element.collation) def visit_fromclause(self, fromclause, **kwargs): return fromclause.name def visit_index(self, index, **kwargs): return index.name def visit_typeclause(self, typeclause, **kw): kw["type_expression"] = typeclause return self.dialect.type_compiler.process(typeclause.type, **kw) def post_process_text(self, text): if self.preparer._double_percents: text = text.replace("%", "%%") return text def escape_literal_column(self, text): if self.preparer._double_percents: text = text.replace("%", "%%") return text def visit_textclause(self, textclause, **kw): def do_bindparam(m): name = m.group(1) if name in textclause._bindparams: return self.process(textclause._bindparams[name], **kw) else: return self.bindparam_string(name, **kw) if not self.stack: self.isplaintext = True # un-escape any \:params return BIND_PARAMS_ESC.sub( lambda m: m.group(1), BIND_PARAMS.sub( do_bindparam, self.post_process_text(textclause.text) ), ) def visit_text_as_from( self, taf, compound_index=None, asfrom=False, parens=True, **kw ): toplevel = not self.stack entry = self._default_stack_entry if toplevel else self.stack[-1] populate_result_map = ( toplevel or ( compound_index == 0 and entry.get("need_result_map_for_compound", False) ) or entry.get("need_result_map_for_nested", False) ) if populate_result_map: self._ordered_columns = ( self._textual_ordered_columns ) = taf.positional for c in taf.column_args: self.process( c, within_columns_clause=True, add_to_result_map=self._add_to_result_map, ) text = self.process(taf.element, **kw) if asfrom and parens: text = "(%s)" % text return text def visit_null(self, expr, **kw): return "NULL" def visit_true(self, expr, **kw): if self.dialect.supports_native_boolean: return "true" else: return "1" def visit_false(self, expr, **kw): if self.dialect.supports_native_boolean: return "false" else: return "0" def visit_clauselist(self, clauselist, **kw): sep = clauselist.operator if sep is None: sep = " " else: sep = OPERATORS[clauselist.operator] text = sep.join( s for s in ( c._compiler_dispatch(self, **kw) for c in clauselist.clauses ) if s ) if clauselist._tuple_values and self.dialect.tuple_in_values: text = "VALUES " + text return text def visit_case(self, clause, **kwargs): x = "CASE " if clause.value is not None: x += clause.value._compiler_dispatch(self, **kwargs) + " " for cond, result in clause.whens: x += ( "WHEN " + cond._compiler_dispatch(self, **kwargs) + " THEN " + result._compiler_dispatch(self, **kwargs) + " " ) if clause.else_ is not None: x += ( "ELSE " + clause.else_._compiler_dispatch(self, **kwargs) + " " ) x += "END" return x def visit_type_coerce(self, type_coerce, **kw): return type_coerce.typed_expression._compiler_dispatch(self, **kw) def visit_cast(self, cast, **kwargs): return "CAST(%s AS %s)" % ( cast.clause._compiler_dispatch(self, **kwargs), cast.typeclause._compiler_dispatch(self, **kwargs), ) def _format_frame_clause(self, range_, **kw): return "%s AND %s" % ( "UNBOUNDED PRECEDING" if range_[0] is elements.RANGE_UNBOUNDED else "CURRENT ROW" if range_[0] is elements.RANGE_CURRENT else "%s PRECEDING" % (self.process(elements.literal(abs(range_[0])), **kw),) if range_[0] < 0 else "%s FOLLOWING" % (self.process(elements.literal(range_[0]), **kw),), "UNBOUNDED FOLLOWING" if range_[1] is elements.RANGE_UNBOUNDED else "CURRENT ROW" if range_[1] is elements.RANGE_CURRENT else "%s PRECEDING" % (self.process(elements.literal(abs(range_[1])), **kw),) if range_[1] < 0 else "%s FOLLOWING" % (self.process(elements.literal(range_[1]), **kw),), ) def visit_over(self, over, **kwargs): if over.range_: range_ = "RANGE BETWEEN %s" % self._format_frame_clause( over.range_, **kwargs ) elif over.rows: range_ = "ROWS BETWEEN %s" % self._format_frame_clause( over.rows, **kwargs ) else: range_ = None return "%s OVER (%s)" % ( over.element._compiler_dispatch(self, **kwargs), " ".join( [ "%s BY %s" % (word, clause._compiler_dispatch(self, **kwargs)) for word, clause in ( ("PARTITION", over.partition_by), ("ORDER", over.order_by), ) if clause is not None and len(clause) ] + ([range_] if range_ else []) ), ) def visit_withingroup(self, withingroup, **kwargs): return "%s WITHIN GROUP (ORDER BY %s)" % ( withingroup.element._compiler_dispatch(self, **kwargs), withingroup.order_by._compiler_dispatch(self, **kwargs), ) def visit_funcfilter(self, funcfilter, **kwargs): return "%s FILTER (WHERE %s)" % ( funcfilter.func._compiler_dispatch(self, **kwargs), funcfilter.criterion._compiler_dispatch(self, **kwargs), ) def visit_extract(self, extract, **kwargs): field = self.extract_map.get(extract.field, extract.field) return "EXTRACT(%s FROM %s)" % ( field, extract.expr._compiler_dispatch(self, **kwargs), ) def visit_function(self, func, add_to_result_map=None, **kwargs): if add_to_result_map is not None: add_to_result_map(func.name, func.name, (), func.type) disp = getattr(self, "visit_%s_func" % func.name.lower(), None) if disp: return disp(func, **kwargs) else: name = FUNCTIONS.get(func.__class__, None) if name: if func._has_args: name += "%(expr)s" else: name = func.name name = ( self.preparer.quote(name) if self.preparer._requires_quotes_illegal_chars(name) or isinstance(name, elements.quoted_name) else name ) name = name + "%(expr)s" return ".".join( [ ( self.preparer.quote(tok) if self.preparer._requires_quotes_illegal_chars(tok) or isinstance(name, elements.quoted_name) else tok ) for tok in func.packagenames ] + [name] ) % {"expr": self.function_argspec(func, **kwargs)} def visit_next_value_func(self, next_value, **kw): return self.visit_sequence(next_value.sequence) def visit_sequence(self, sequence, **kw): raise NotImplementedError( "Dialect '%s' does not support sequence increments." % self.dialect.name ) def function_argspec(self, func, **kwargs): return func.clause_expr._compiler_dispatch(self, **kwargs) def visit_compound_select( self, cs, asfrom=False, parens=True, compound_index=0, **kwargs ): toplevel = not self.stack entry = self._default_stack_entry if toplevel else self.stack[-1] need_result_map = toplevel or ( compound_index == 0 and entry.get("need_result_map_for_compound", False) ) self.stack.append( { "correlate_froms": entry["correlate_froms"], "asfrom_froms": entry["asfrom_froms"], "selectable": cs, "need_result_map_for_compound": need_result_map, } ) keyword = self.compound_keywords.get(cs.keyword) text = (" " + keyword + " ").join( ( c._compiler_dispatch( self, asfrom=asfrom, parens=False, compound_index=i, **kwargs ) for i, c in enumerate(cs.selects) ) ) text += self.group_by_clause(cs, **dict(asfrom=asfrom, **kwargs)) text += self.order_by_clause(cs, **kwargs) text += ( (cs._limit_clause is not None or cs._offset_clause is not None) and self.limit_clause(cs, **kwargs) or "" ) if self.ctes and toplevel: text = self._render_cte_clause() + text self.stack.pop(-1) if asfrom and parens: return "(" + text + ")" else: return text def _get_operator_dispatch(self, operator_, qualifier1, qualifier2): attrname = "visit_%s_%s%s" % ( operator_.__name__, qualifier1, "_" + qualifier2 if qualifier2 else "", ) return getattr(self, attrname, None) def visit_unary(self, unary, **kw): if unary.operator: if unary.modifier: raise exc.CompileError( "Unary expression does not support operator " "and modifier simultaneously" ) disp = self._get_operator_dispatch( unary.operator, "unary", "operator" ) if disp: return disp(unary, unary.operator, **kw) else: return self._generate_generic_unary_operator( unary, OPERATORS[unary.operator], **kw ) elif unary.modifier: disp = self._get_operator_dispatch( unary.modifier, "unary", "modifier" ) if disp: return disp(unary, unary.modifier, **kw) else: return self._generate_generic_unary_modifier( unary, OPERATORS[unary.modifier], **kw ) else: raise exc.CompileError( "Unary expression has no operator or modifier" ) def visit_istrue_unary_operator(self, element, operator, **kw): if ( element._is_implicitly_boolean or self.dialect.supports_native_boolean ): return self.process(element.element, **kw) else: return "%s = 1" % self.process(element.element, **kw) def visit_isfalse_unary_operator(self, element, operator, **kw): if ( element._is_implicitly_boolean or self.dialect.supports_native_boolean ): return "NOT %s" % self.process(element.element, **kw) else: return "%s = 0" % self.process(element.element, **kw) def visit_notmatch_op_binary(self, binary, operator, **kw): return "NOT %s" % self.visit_binary( binary, override_operator=operators.match_op ) def _emit_empty_in_warning(self): util.warn( "The IN-predicate was invoked with an " "empty sequence. This results in a " "contradiction, which nonetheless can be " "expensive to evaluate. Consider alternative " "strategies for improved performance." ) def visit_empty_in_op_binary(self, binary, operator, **kw): if self.dialect._use_static_in: return "1 != 1" else: if self.dialect._warn_on_empty_in: self._emit_empty_in_warning() return self.process(binary.left != binary.left) def visit_empty_notin_op_binary(self, binary, operator, **kw): if self.dialect._use_static_in: return "1 = 1" else: if self.dialect._warn_on_empty_in: self._emit_empty_in_warning() return self.process(binary.left == binary.left) def visit_empty_set_expr(self, element_types): raise NotImplementedError( "Dialect '%s' does not support empty set expression." % self.dialect.name ) def visit_binary( self, binary, override_operator=None, eager_grouping=False, **kw ): # don't allow "? = ?" to render if ( self.ansi_bind_rules and isinstance(binary.left, elements.BindParameter) and isinstance(binary.right, elements.BindParameter) ): kw["literal_binds"] = True operator_ = override_operator or binary.operator disp = self._get_operator_dispatch(operator_, "binary", None) if disp: return disp(binary, operator_, **kw) else: try: opstring = OPERATORS[operator_] except KeyError as err: util.raise_( exc.UnsupportedCompilationError(self, operator_), replace_context=err, ) else: return self._generate_generic_binary(binary, opstring, **kw) def visit_function_as_comparison_op_binary(self, element, operator, **kw): return self.process(element.sql_function, **kw) def visit_mod_binary(self, binary, operator, **kw): if self.preparer._double_percents: return ( self.process(binary.left, **kw) + " %% " + self.process(binary.right, **kw) ) else: return ( self.process(binary.left, **kw) + " % " + self.process(binary.right, **kw) ) def visit_custom_op_binary(self, element, operator, **kw): kw["eager_grouping"] = operator.eager_grouping return self._generate_generic_binary( element, " " + operator.opstring + " ", **kw ) def visit_custom_op_unary_operator(self, element, operator, **kw): return self._generate_generic_unary_operator( element, operator.opstring + " ", **kw ) def visit_custom_op_unary_modifier(self, element, operator, **kw): return self._generate_generic_unary_modifier( element, " " + operator.opstring, **kw ) def _generate_generic_binary( self, binary, opstring, eager_grouping=False, **kw ): _in_binary = kw.get("_in_binary", False) kw["_in_binary"] = True text = ( binary.left._compiler_dispatch( self, eager_grouping=eager_grouping, **kw ) + opstring + binary.right._compiler_dispatch( self, eager_grouping=eager_grouping, **kw ) ) if _in_binary and eager_grouping: text = "(%s)" % text return text def _generate_generic_unary_operator(self, unary, opstring, **kw): return opstring + unary.element._compiler_dispatch(self, **kw) def _generate_generic_unary_modifier(self, unary, opstring, **kw): return unary.element._compiler_dispatch(self, **kw) + opstring @util.memoized_property def _like_percent_literal(self): return elements.literal_column("'%'", type_=sqltypes.STRINGTYPE) def visit_contains_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__add__(binary.right).__add__(percent) return self.visit_like_op_binary(binary, operator, **kw) def visit_notcontains_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__add__(binary.right).__add__(percent) return self.visit_notlike_op_binary(binary, operator, **kw) def visit_startswith_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__radd__(binary.right) return self.visit_like_op_binary(binary, operator, **kw) def visit_notstartswith_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__radd__(binary.right) return self.visit_notlike_op_binary(binary, operator, **kw) def visit_endswith_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__add__(binary.right) return self.visit_like_op_binary(binary, operator, **kw) def visit_notendswith_op_binary(self, binary, operator, **kw): binary = binary._clone() percent = self._like_percent_literal binary.right = percent.__add__(binary.right) return self.visit_notlike_op_binary(binary, operator, **kw) def visit_like_op_binary(self, binary, operator, **kw): escape = binary.modifiers.get("escape", None) # TODO: use ternary here, not "and"/ "or" return "%s LIKE %s" % ( binary.left._compiler_dispatch(self, **kw), binary.right._compiler_dispatch(self, **kw), ) + ( " ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE) if escape else "" ) def visit_notlike_op_binary(self, binary, operator, **kw): escape = binary.modifiers.get("escape", None) return "%s NOT LIKE %s" % ( binary.left._compiler_dispatch(self, **kw), binary.right._compiler_dispatch(self, **kw), ) + ( " ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE) if escape else "" ) def visit_ilike_op_binary(self, binary, operator, **kw): escape = binary.modifiers.get("escape", None) return "lower(%s) LIKE lower(%s)" % ( binary.left._compiler_dispatch(self, **kw), binary.right._compiler_dispatch(self, **kw), ) + ( " ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE) if escape else "" ) def visit_notilike_op_binary(self, binary, operator, **kw): escape = binary.modifiers.get("escape", None) return "lower(%s) NOT LIKE lower(%s)" % ( binary.left._compiler_dispatch(self, **kw), binary.right._compiler_dispatch(self, **kw), ) + ( " ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE) if escape else "" ) def visit_between_op_binary(self, binary, operator, **kw): symmetric = binary.modifiers.get("symmetric", False) return self._generate_generic_binary( binary, " BETWEEN SYMMETRIC " if symmetric else " BETWEEN ", **kw ) def visit_notbetween_op_binary(self, binary, operator, **kw): symmetric = binary.modifiers.get("symmetric", False) return self._generate_generic_binary( binary, " NOT BETWEEN SYMMETRIC " if symmetric else " NOT BETWEEN ", **kw ) def visit_bindparam( self, bindparam, within_columns_clause=False, literal_binds=False, skip_bind_expression=False, **kwargs ): if not skip_bind_expression: impl = bindparam.type.dialect_impl(self.dialect) if impl._has_bind_expression: bind_expression = impl.bind_expression(bindparam) return self.process( bind_expression, skip_bind_expression=True, within_columns_clause=within_columns_clause, literal_binds=literal_binds, **kwargs ) if literal_binds or (within_columns_clause and self.ansi_bind_rules): if bindparam.value is None and bindparam.callable is None: raise exc.CompileError( "Bind parameter '%s' without a " "renderable value not allowed here." % bindparam.key ) return self.render_literal_bindparam( bindparam, within_columns_clause=True, **kwargs ) name = self._truncate_bindparam(bindparam) if name in self.binds: existing = self.binds[name] if existing is not bindparam: if ( existing.unique or bindparam.unique ) and not existing.proxy_set.intersection(bindparam.proxy_set): raise exc.CompileError( "Bind parameter '%s' conflicts with " "unique bind parameter of the same name" % bindparam.key ) elif existing._is_crud or bindparam._is_crud: raise exc.CompileError( "bindparam() name '%s' is reserved " "for automatic usage in the VALUES or SET " "clause of this " "insert/update statement. Please use a " "name other than column name when using bindparam() " "with insert() or update() (for example, 'b_%s')." % (bindparam.key, bindparam.key) ) self.binds[bindparam.key] = self.binds[name] = bindparam return self.bindparam_string( name, expanding=bindparam.expanding, **kwargs ) def render_literal_bindparam(self, bindparam, **kw): value = bindparam.effective_value return self.render_literal_value(value, bindparam.type) def render_literal_value(self, value, type_): """Render the value of a bind parameter as a quoted literal. This is used for statement sections that do not accept bind parameters on the target driver/database. This should be implemented by subclasses using the quoting services of the DBAPI. """ processor = type_._cached_literal_processor(self.dialect) if processor: return processor(value) else: raise NotImplementedError( "Don't know how to literal-quote value %r" % value ) def _truncate_bindparam(self, bindparam): if bindparam in self.bind_names: return self.bind_names[bindparam] bind_name = bindparam.key if isinstance(bind_name, elements._truncated_label): bind_name = self._truncated_identifier("bindparam", bind_name) # add to bind_names for translation self.bind_names[bindparam] = bind_name return bind_name def _truncated_identifier(self, ident_class, name): if (ident_class, name) in self.truncated_names: return self.truncated_names[(ident_class, name)] anonname = name.apply_map(self.anon_map) if len(anonname) > self.label_length - 6: counter = self.truncated_names.get(ident_class, 1) truncname = ( anonname[0 : max(self.label_length - 6, 0)] + "_" + hex(counter)[2:] ) self.truncated_names[ident_class] = counter + 1 else: truncname = anonname self.truncated_names[(ident_class, name)] = truncname return truncname def _anonymize(self, name): return name % self.anon_map def bindparam_string( self, name, positional_names=None, expanding=False, **kw ): if self.positional: if positional_names is not None: positional_names.append(name) else: self.positiontup.append(name) if expanding: self.contains_expanding_parameters = True return "([EXPANDING_%s])" % name else: return self.bindtemplate % {"name": name} def visit_cte( self, cte, asfrom=False, ashint=False, fromhints=None, visiting_cte=None, **kwargs ): self._init_cte_state() kwargs["visiting_cte"] = cte if isinstance(cte.name, elements._truncated_label): cte_name = self._truncated_identifier("alias", cte.name) else: cte_name = cte.name is_new_cte = True embedded_in_current_named_cte = False if cte_name in self.ctes_by_name: existing_cte = self.ctes_by_name[cte_name] embedded_in_current_named_cte = visiting_cte is existing_cte # we've generated a same-named CTE that we are enclosed in, # or this is the same CTE. just return the name. if cte in existing_cte._restates or cte is existing_cte: is_new_cte = False elif existing_cte in cte._restates: # we've generated a same-named CTE that is # enclosed in us - we take precedence, so # discard the text for the "inner". del self.ctes[existing_cte] else: raise exc.CompileError( "Multiple, unrelated CTEs found with " "the same name: %r" % cte_name ) if asfrom or is_new_cte: if cte._cte_alias is not None: pre_alias_cte = cte._cte_alias cte_pre_alias_name = cte._cte_alias.name if isinstance(cte_pre_alias_name, elements._truncated_label): cte_pre_alias_name = self._truncated_identifier( "alias", cte_pre_alias_name ) else: pre_alias_cte = cte cte_pre_alias_name = None if is_new_cte: self.ctes_by_name[cte_name] = cte # look for embedded DML ctes and propagate autocommit if ( "autocommit" in cte.element._execution_options and "autocommit" not in self.execution_options ): self.execution_options = self.execution_options.union( { "autocommit": cte.element._execution_options[ "autocommit" ] } ) if pre_alias_cte not in self.ctes: self.visit_cte(pre_alias_cte, **kwargs) if not cte_pre_alias_name and cte not in self.ctes: if cte.recursive: self.ctes_recursive = True text = self.preparer.format_alias(cte, cte_name) if cte.recursive: if isinstance(cte.original, selectable.Select): col_source = cte.original elif isinstance(cte.original, selectable.CompoundSelect): col_source = cte.original.selects[0] else: assert False recur_cols = [ c for c in util.unique_list(col_source.inner_columns) if c is not None ] text += "(%s)" % ( ", ".join( self.preparer.format_column(ident) for ident in recur_cols ) ) if self.positional: kwargs["positional_names"] = self.cte_positional[cte] = [] text += " AS %s\n%s" % ( self._generate_prefixes(cte, cte._prefixes, **kwargs), cte.original._compiler_dispatch( self, asfrom=True, **kwargs ), ) if cte._suffixes: text += " " + self._generate_prefixes( cte, cte._suffixes, **kwargs ) self.ctes[cte] = text if asfrom: if not is_new_cte and embedded_in_current_named_cte: return self.preparer.format_alias(cte, cte_name) if cte_pre_alias_name: text = self.preparer.format_alias(cte, cte_pre_alias_name) if self.preparer._requires_quotes(cte_name): cte_name = self.preparer.quote(cte_name) text += self.get_render_as_alias_suffix(cte_name) return text else: return self.preparer.format_alias(cte, cte_name) def visit_alias( self, alias, asfrom=False, ashint=False, iscrud=False, fromhints=None, **kwargs ): if asfrom or ashint: if isinstance(alias.name, elements._truncated_label): alias_name = self._truncated_identifier("alias", alias.name) else: alias_name = alias.name if ashint: return self.preparer.format_alias(alias, alias_name) elif asfrom: ret = alias.original._compiler_dispatch( self, asfrom=True, **kwargs ) + self.get_render_as_alias_suffix( self.preparer.format_alias(alias, alias_name) ) if fromhints and alias in fromhints: ret = self.format_from_hint_text( ret, alias, fromhints[alias], iscrud ) return ret else: return alias.original._compiler_dispatch(self, **kwargs) def visit_lateral(self, lateral, **kw): kw["lateral"] = True return "LATERAL %s" % self.visit_alias(lateral, **kw) def visit_tablesample(self, tablesample, asfrom=False, **kw): text = "%s TABLESAMPLE %s" % ( self.visit_alias(tablesample, asfrom=True, **kw), tablesample._get_method()._compiler_dispatch(self, **kw), ) if tablesample.seed is not None: text += " REPEATABLE (%s)" % ( tablesample.seed._compiler_dispatch(self, **kw) ) return text def get_render_as_alias_suffix(self, alias_name_text): return " AS " + alias_name_text def _add_to_result_map(self, keyname, name, objects, type_): self._result_columns.append((keyname, name, objects, type_)) def _label_select_column( self, select, column, populate_result_map, asfrom, column_clause_args, name=None, within_columns_clause=True, need_column_expressions=False, ): """produce labeled columns present in a select().""" impl = column.type.dialect_impl(self.dialect) if impl._has_column_expression and ( need_column_expressions or populate_result_map ): col_expr = impl.column_expression(column) if populate_result_map: def add_to_result_map(keyname, name, objects, type_): self._add_to_result_map( keyname, name, (column,) + objects, type_ ) else: add_to_result_map = None else: col_expr = column if populate_result_map: add_to_result_map = self._add_to_result_map else: add_to_result_map = None if not within_columns_clause: result_expr = col_expr elif isinstance(column, elements.Label): if col_expr is not column: result_expr = _CompileLabel( col_expr, column.name, alt_names=(column.element,) ) else: result_expr = col_expr elif select is not None and name: result_expr = _CompileLabel( col_expr, name, alt_names=(column._key_label,) ) elif ( asfrom and isinstance(column, elements.ColumnClause) and not column.is_literal and column.table is not None and not isinstance(column.table, selectable.Select) ): result_expr = _CompileLabel( col_expr, elements._as_truncated(column.name), alt_names=(column.key,), ) elif ( not isinstance(column, elements.TextClause) and ( not isinstance(column, elements.UnaryExpression) or column.wraps_column_expression ) and ( not hasattr(column, "name") or isinstance(column, functions.Function) ) ): result_expr = _CompileLabel(col_expr, column.anon_label) elif col_expr is not column: # TODO: are we sure "column" has a .name and .key here ? # assert isinstance(column, elements.ColumnClause) result_expr = _CompileLabel( col_expr, elements._as_truncated(column.name), alt_names=(column.key,), ) else: result_expr = col_expr column_clause_args.update( within_columns_clause=within_columns_clause, add_to_result_map=add_to_result_map, ) return result_expr._compiler_dispatch(self, **column_clause_args) def format_from_hint_text(self, sqltext, table, hint, iscrud): hinttext = self.get_from_hint_text(table, hint) if hinttext: sqltext += " " + hinttext return sqltext def get_select_hint_text(self, byfroms): return None def get_from_hint_text(self, table, text): return None def get_crud_hint_text(self, table, text): return None def get_statement_hint_text(self, hint_texts): return " ".join(hint_texts) def _transform_select_for_nested_joins(self, select): """Rewrite any "a JOIN (b JOIN c)" expression as "a JOIN (select * from b JOIN c) AS anon", to support databases that can't parse a parenthesized join correctly (i.e. sqlite < 3.7.16). """ cloned = {} column_translate = [{}] def visit(element, **kw): if element in column_translate[-1]: return column_translate[-1][element] elif element in cloned: return cloned[element] newelem = cloned[element] = element._clone() if ( newelem.is_selectable and newelem._is_join and isinstance(newelem.right, selectable.FromGrouping) ): newelem._reset_exported() newelem.left = visit(newelem.left, **kw) right = visit(newelem.right, **kw) selectable_ = selectable.Select( [right.element], use_labels=True ).alias() for c in selectable_.c: c._key_label = c.key c._label = c.name translate_dict = dict( zip(newelem.right.element.c, selectable_.c) ) # translating from both the old and the new # because different select() structures will lead us # to traverse differently translate_dict[right.element.left] = selectable_ translate_dict[right.element.right] = selectable_ translate_dict[newelem.right.element.left] = selectable_ translate_dict[newelem.right.element.right] = selectable_ # propagate translations that we've gained # from nested visit(newelem.right) outwards # to the enclosing select here. this happens # only when we have more than one level of right # join nesting, i.e. "a JOIN (b JOIN (c JOIN d))" for k, v in list(column_translate[-1].items()): if v in translate_dict: # remarkably, no current ORM tests (May 2013) # hit this condition, only test_join_rewriting # does. column_translate[-1][k] = translate_dict[v] column_translate[-1].update(translate_dict) newelem.right = selectable_ newelem.onclause = visit(newelem.onclause, **kw) elif newelem._is_from_container: # if we hit an Alias, CompoundSelect or ScalarSelect, put a # marker in the stack. kw["transform_clue"] = "select_container" newelem._copy_internals(clone=visit, **kw) elif newelem.is_selectable and newelem._is_select: barrier_select = ( kw.get("transform_clue", None) == "select_container" ) # if we're still descended from an # Alias/CompoundSelect/ScalarSelect, we're # in a FROM clause, so start with a new translate collection if barrier_select: column_translate.append({}) kw["transform_clue"] = "inside_select" newelem._copy_internals(clone=visit, **kw) if barrier_select: del column_translate[-1] else: newelem._copy_internals(clone=visit, **kw) return newelem return visit(select) def _transform_result_map_for_nested_joins( self, select, transformed_select ): inner_col = dict( (c._key_label, c) for c in transformed_select.inner_columns ) d = dict((inner_col[c._key_label], c) for c in select.inner_columns) self._result_columns = [ (key, name, tuple([d.get(col, col) for col in objs]), typ) for key, name, objs, typ in self._result_columns ] _default_stack_entry = util.immutabledict( [("correlate_froms", frozenset()), ("asfrom_froms", frozenset())] ) def _display_froms_for_select(self, select, asfrom, lateral=False): # utility method to help external dialects # get the correct from list for a select. # specifically the oracle dialect needs this feature # right now. toplevel = not self.stack entry = self._default_stack_entry if toplevel else self.stack[-1] correlate_froms = entry["correlate_froms"] asfrom_froms = entry["asfrom_froms"] if asfrom and not lateral: froms = select._get_display_froms( explicit_correlate_froms=correlate_froms.difference( asfrom_froms ), implicit_correlate_froms=(), ) else: froms = select._get_display_froms( explicit_correlate_froms=correlate_froms, implicit_correlate_froms=asfrom_froms, ) return froms def visit_select( self, select, asfrom=False, parens=True, fromhints=None, compound_index=0, nested_join_translation=False, select_wraps_for=None, lateral=False, **kwargs ): needs_nested_translation = ( select.use_labels and not nested_join_translation and not self.stack and not self.dialect.supports_right_nested_joins ) if needs_nested_translation: transformed_select = self._transform_select_for_nested_joins( select ) text = self.visit_select( transformed_select, asfrom=asfrom, parens=parens, fromhints=fromhints, compound_index=compound_index, nested_join_translation=True, **kwargs ) toplevel = not self.stack entry = self._default_stack_entry if toplevel else self.stack[-1] populate_result_map = need_column_expressions = ( toplevel or entry.get("need_result_map_for_compound", False) or entry.get("need_result_map_for_nested", False) ) if compound_index > 0: populate_result_map = False # this was first proposed as part of #3372; however, it is not # reached in current tests and could possibly be an assertion # instead. if not populate_result_map and "add_to_result_map" in kwargs: del kwargs["add_to_result_map"] if needs_nested_translation: if populate_result_map: self._transform_result_map_for_nested_joins( select, transformed_select ) return text froms = self._setup_select_stack(select, entry, asfrom, lateral) column_clause_args = kwargs.copy() column_clause_args.update( {"within_label_clause": False, "within_columns_clause": False} ) text = "SELECT " # we're off to a good start ! if select._hints: hint_text, byfrom = self._setup_select_hints(select) if hint_text: text += hint_text + " " else: byfrom = None if select._prefixes: text += self._generate_prefixes(select, select._prefixes, **kwargs) text += self.get_select_precolumns(select, **kwargs) # the actual list of columns to print in the SELECT column list. inner_columns = [ c for c in [ self._label_select_column( select, column, populate_result_map, asfrom, column_clause_args, name=name, need_column_expressions=need_column_expressions, ) for name, column in select._columns_plus_names ] if c is not None ] if populate_result_map and select_wraps_for is not None: # if this select is a compiler-generated wrapper, # rewrite the targeted columns in the result map translate = dict( zip( [name for (key, name) in select._columns_plus_names], [ name for (key, name) in select_wraps_for._columns_plus_names ], ) ) self._result_columns = [ (key, name, tuple(translate.get(o, o) for o in obj), type_) for key, name, obj, type_ in self._result_columns ] text = self._compose_select_body( text, select, inner_columns, froms, byfrom, kwargs ) if select._statement_hints: per_dialect = [ ht for (dialect_name, ht) in select._statement_hints if dialect_name in ("*", self.dialect.name) ] if per_dialect: text += " " + self.get_statement_hint_text(per_dialect) if self.ctes and toplevel: text = self._render_cte_clause() + text if select._suffixes: text += " " + self._generate_prefixes( select, select._suffixes, **kwargs ) self.stack.pop(-1) if (asfrom or lateral) and parens: return "(" + text + ")" else: return text def _setup_select_hints(self, select): byfrom = dict( [ ( from_, hinttext % {"name": from_._compiler_dispatch(self, ashint=True)}, ) for (from_, dialect), hinttext in select._hints.items() if dialect in ("*", self.dialect.name) ] ) hint_text = self.get_select_hint_text(byfrom) return hint_text, byfrom def _setup_select_stack(self, select, entry, asfrom, lateral): correlate_froms = entry["correlate_froms"] asfrom_froms = entry["asfrom_froms"] if asfrom and not lateral: froms = select._get_display_froms( explicit_correlate_froms=correlate_froms.difference( asfrom_froms ), implicit_correlate_froms=(), ) else: froms = select._get_display_froms( explicit_correlate_froms=correlate_froms, implicit_correlate_froms=asfrom_froms, ) new_correlate_froms = set(selectable._from_objects(*froms)) all_correlate_froms = new_correlate_froms.union(correlate_froms) new_entry = { "asfrom_froms": new_correlate_froms, "correlate_froms": all_correlate_froms, "selectable": select, } self.stack.append(new_entry) return froms def _compose_select_body( self, text, select, inner_columns, froms, byfrom, kwargs ): text += ", ".join(inner_columns) if froms: text += " \nFROM " if select._hints: text += ", ".join( [ f._compiler_dispatch( self, asfrom=True, fromhints=byfrom, **kwargs ) for f in froms ] ) else: text += ", ".join( [ f._compiler_dispatch(self, asfrom=True, **kwargs) for f in froms ] ) else: text += self.default_from() if select._whereclause is not None: t = select._whereclause._compiler_dispatch(self, **kwargs) if t: text += " \nWHERE " + t if select._group_by_clause.clauses: text += self.group_by_clause(select, **kwargs) if select._having is not None: t = select._having._compiler_dispatch(self, **kwargs) if t: text += " \nHAVING " + t if select._order_by_clause.clauses: text += self.order_by_clause(select, **kwargs) if ( select._limit_clause is not None or select._offset_clause is not None ): text += self.limit_clause(select, **kwargs) if select._for_update_arg is not None: text += self.for_update_clause(select, **kwargs) return text def _generate_prefixes(self, stmt, prefixes, **kw): clause = " ".join( prefix._compiler_dispatch(self, **kw) for prefix, dialect_name in prefixes if dialect_name is None or dialect_name == self.dialect.name ) if clause: clause += " " return clause def _render_cte_clause(self): if self.positional: self.positiontup = ( sum([self.cte_positional[cte] for cte in self.ctes], []) + self.positiontup ) cte_text = self.get_cte_preamble(self.ctes_recursive) + " " cte_text += ", \n".join([txt for txt in self.ctes.values()]) cte_text += "\n " return cte_text def get_cte_preamble(self, recursive): if recursive: return "WITH RECURSIVE" else: return "WITH" def get_select_precolumns(self, select, **kw): """Called when building a ``SELECT`` statement, position is just before column list. """ return select._distinct and "DISTINCT " or "" def group_by_clause(self, select, **kw): """allow dialects to customize how GROUP BY is rendered.""" group_by = select._group_by_clause._compiler_dispatch(self, **kw) if group_by: return " GROUP BY " + group_by else: return "" def order_by_clause(self, select, **kw): """allow dialects to customize how ORDER BY is rendered.""" order_by = select._order_by_clause._compiler_dispatch(self, **kw) if order_by: return " ORDER BY " + order_by else: return "" def for_update_clause(self, select, **kw): return " FOR UPDATE" def returning_clause(self, stmt, returning_cols): raise exc.CompileError( "RETURNING is not supported by this " "dialect's statement compiler." ) def limit_clause(self, select, **kw): text = "" if select._limit_clause is not None: text += "\n LIMIT " + self.process(select._limit_clause, **kw) if select._offset_clause is not None: if select._limit_clause is None: text += "\n LIMIT -1" text += " OFFSET " + self.process(select._offset_clause, **kw) return text def visit_table( self, table, asfrom=False, iscrud=False, ashint=False, fromhints=None, use_schema=True, **kwargs ): if asfrom or ashint: effective_schema = self.preparer.schema_for_object(table) if use_schema and effective_schema: ret = ( self.preparer.quote_schema(effective_schema) + "." + self.preparer.quote(table.name) ) else: ret = self.preparer.quote(table.name) if fromhints and table in fromhints: ret = self.format_from_hint_text( ret, table, fromhints[table], iscrud ) return ret else: return "" def visit_join(self, join, asfrom=False, **kwargs): if join.full: join_type = " FULL OUTER JOIN " elif join.isouter: join_type = " LEFT OUTER JOIN " else: join_type = " JOIN " return ( join.left._compiler_dispatch(self, asfrom=True, **kwargs) + join_type + join.right._compiler_dispatch(self, asfrom=True, **kwargs) + " ON " + join.onclause._compiler_dispatch(self, **kwargs) ) def _setup_crud_hints(self, stmt, table_text): dialect_hints = dict( [ (table, hint_text) for (table, dialect), hint_text in stmt._hints.items() if dialect in ("*", self.dialect.name) ] ) if stmt.table in dialect_hints: table_text = self.format_from_hint_text( table_text, stmt.table, dialect_hints[stmt.table], True ) return dialect_hints, table_text def visit_insert(self, insert_stmt, asfrom=False, **kw): toplevel = not self.stack self.stack.append( { "correlate_froms": set(), "asfrom_froms": set(), "selectable": insert_stmt, } ) crud_params = crud._setup_crud_params( self, insert_stmt, crud.ISINSERT, **kw ) if ( not crud_params and not self.dialect.supports_default_values and not self.dialect.supports_empty_insert ): raise exc.CompileError( "The '%s' dialect with current database " "version settings does not support empty " "inserts." % self.dialect.name ) if insert_stmt._has_multi_parameters: if not self.dialect.supports_multivalues_insert: raise exc.CompileError( "The '%s' dialect with current database " "version settings does not support " "in-place multirow inserts." % self.dialect.name ) crud_params_single = crud_params[0] else: crud_params_single = crud_params preparer = self.preparer supports_default_values = self.dialect.supports_default_values text = "INSERT " if insert_stmt._prefixes: text += self._generate_prefixes( insert_stmt, insert_stmt._prefixes, **kw ) text += "INTO " table_text = preparer.format_table(insert_stmt.table) if insert_stmt._hints: _, table_text = self._setup_crud_hints(insert_stmt, table_text) text += table_text if crud_params_single or not supports_default_values: text += " (%s)" % ", ".join( [preparer.format_column(c[0]) for c in crud_params_single] ) if self.returning or insert_stmt._returning: returning_clause = self.returning_clause( insert_stmt, self.returning or insert_stmt._returning ) if self.returning_precedes_values: text += " " + returning_clause else: returning_clause = None if insert_stmt.select is not None: select_text = self.process(self._insert_from_select, **kw) if self.ctes and toplevel and self.dialect.cte_follows_insert: text += " %s%s" % (self._render_cte_clause(), select_text) else: text += " %s" % select_text elif not crud_params and supports_default_values: text += " DEFAULT VALUES" elif insert_stmt._has_multi_parameters: text += " VALUES %s" % ( ", ".join( "(%s)" % (", ".join(c[1] for c in crud_param_set)) for crud_param_set in crud_params ) ) else: insert_single_values_expr = ", ".join([c[1] for c in crud_params]) text += " VALUES (%s)" % insert_single_values_expr if toplevel: self.insert_single_values_expr = insert_single_values_expr if insert_stmt._post_values_clause is not None: post_values_clause = self.process( insert_stmt._post_values_clause, **kw ) if post_values_clause: text += " " + post_values_clause if returning_clause and not self.returning_precedes_values: text += " " + returning_clause if self.ctes and toplevel and not self.dialect.cte_follows_insert: text = self._render_cte_clause() + text self.stack.pop(-1) if asfrom: return "(" + text + ")" else: return text def update_limit_clause(self, update_stmt): """Provide a hook for MySQL to add LIMIT to the UPDATE""" return None def update_tables_clause(self, update_stmt, from_table, extra_froms, **kw): """Provide a hook to override the initial table clause in an UPDATE statement. MySQL overrides this. """ kw["asfrom"] = True return from_table._compiler_dispatch(self, iscrud=True, **kw) def update_from_clause( self, update_stmt, from_table, extra_froms, from_hints, **kw ): """Provide a hook to override the generation of an UPDATE..FROM clause. MySQL and MSSQL override this. """ raise NotImplementedError( "This backend does not support multiple-table " "criteria within UPDATE" ) def visit_update(self, update_stmt, asfrom=False, **kw): toplevel = not self.stack extra_froms = update_stmt._extra_froms is_multitable = bool(extra_froms) if is_multitable: # main table might be a JOIN main_froms = set(selectable._from_objects(update_stmt.table)) render_extra_froms = [ f for f in extra_froms if f not in main_froms ] correlate_froms = main_froms.union(extra_froms) else: render_extra_froms = [] correlate_froms = {update_stmt.table} self.stack.append( { "correlate_froms": correlate_froms, "asfrom_froms": correlate_froms, "selectable": update_stmt, } ) text = "UPDATE " if update_stmt._prefixes: text += self._generate_prefixes( update_stmt, update_stmt._prefixes, **kw ) table_text = self.update_tables_clause( update_stmt, update_stmt.table, render_extra_froms, **kw ) crud_params = crud._setup_crud_params( self, update_stmt, crud.ISUPDATE, **kw ) if update_stmt._hints: dialect_hints, table_text = self._setup_crud_hints( update_stmt, table_text ) else: dialect_hints = None text += table_text text += " SET " include_table = ( is_multitable and self.render_table_with_column_in_update_from ) text += ", ".join( c[0]._compiler_dispatch(self, include_table=include_table) + "=" + c[1] for c in crud_params ) if self.returning or update_stmt._returning: if self.returning_precedes_values: text += " " + self.returning_clause( update_stmt, self.returning or update_stmt._returning ) if extra_froms: extra_from_text = self.update_from_clause( update_stmt, update_stmt.table, render_extra_froms, dialect_hints, **kw ) if extra_from_text: text += " " + extra_from_text if update_stmt._whereclause is not None: t = self.process(update_stmt._whereclause, **kw) if t: text += " WHERE " + t limit_clause = self.update_limit_clause(update_stmt) if limit_clause: text += " " + limit_clause if ( self.returning or update_stmt._returning ) and not self.returning_precedes_values: text += " " + self.returning_clause( update_stmt, self.returning or update_stmt._returning ) if self.ctes and toplevel: text = self._render_cte_clause() + text self.stack.pop(-1) if asfrom: return "(" + text + ")" else: return text @util.memoized_property def _key_getters_for_crud_column(self): return crud._key_getters_for_crud_column(self, self.statement) def delete_extra_from_clause( self, update_stmt, from_table, extra_froms, from_hints, **kw ): """Provide a hook to override the generation of an DELETE..FROM clause. This can be used to implement DELETE..USING for example. MySQL and MSSQL override this. """ raise NotImplementedError( "This backend does not support multiple-table " "criteria within DELETE" ) def delete_table_clause(self, delete_stmt, from_table, extra_froms): return from_table._compiler_dispatch(self, asfrom=True, iscrud=True) def visit_delete(self, delete_stmt, asfrom=False, **kw): toplevel = not self.stack crud._setup_crud_params(self, delete_stmt, crud.ISDELETE, **kw) extra_froms = delete_stmt._extra_froms correlate_froms = {delete_stmt.table}.union(extra_froms) self.stack.append( { "correlate_froms": correlate_froms, "asfrom_froms": correlate_froms, "selectable": delete_stmt, } ) text = "DELETE " if delete_stmt._prefixes: text += self._generate_prefixes( delete_stmt, delete_stmt._prefixes, **kw ) text += "FROM " table_text = self.delete_table_clause( delete_stmt, delete_stmt.table, extra_froms ) if delete_stmt._hints: dialect_hints, table_text = self._setup_crud_hints( delete_stmt, table_text ) else: dialect_hints = None text += table_text if delete_stmt._returning: if self.returning_precedes_values: text += " " + self.returning_clause( delete_stmt, delete_stmt._returning ) if extra_froms: extra_from_text = self.delete_extra_from_clause( delete_stmt, delete_stmt.table, extra_froms, dialect_hints, **kw ) if extra_from_text: text += " " + extra_from_text if delete_stmt._whereclause is not None: t = delete_stmt._whereclause._compiler_dispatch(self, **kw) if t: text += " WHERE " + t if delete_stmt._returning and not self.returning_precedes_values: text += " " + self.returning_clause( delete_stmt, delete_stmt._returning ) if self.ctes and toplevel: text = self._render_cte_clause() + text self.stack.pop(-1) if asfrom: return "(" + text + ")" else: return text def visit_savepoint(self, savepoint_stmt): return "SAVEPOINT %s" % self.preparer.format_savepoint(savepoint_stmt) def visit_rollback_to_savepoint(self, savepoint_stmt): return "ROLLBACK TO SAVEPOINT %s" % self.preparer.format_savepoint( savepoint_stmt ) def visit_release_savepoint(self, savepoint_stmt): return "RELEASE SAVEPOINT %s" % self.preparer.format_savepoint( savepoint_stmt ) class StrSQLCompiler(SQLCompiler): """A :class:`.SQLCompiler` subclass which allows a small selection of non-standard SQL features to render into a string value. The :class:`.StrSQLCompiler` is invoked whenever a Core expression element is directly stringified without calling upon the :meth:`_expression.ClauseElement.compile` method. It can render a limited set of non-standard SQL constructs to assist in basic stringification, however for more substantial custom or dialect-specific SQL constructs, it will be necessary to make use of :meth:`_expression.ClauseElement.compile` directly. .. seealso:: :ref:`faq_sql_expression_string` """ def _fallback_column_name(self, column): return "<name unknown>" def visit_getitem_binary(self, binary, operator, **kw): return "%s[%s]" % ( self.process(binary.left, **kw), self.process(binary.right, **kw), ) def visit_json_getitem_op_binary(self, binary, operator, **kw): return self.visit_getitem_binary(binary, operator, **kw) def visit_json_path_getitem_op_binary(self, binary, operator, **kw): return self.visit_getitem_binary(binary, operator, **kw) def visit_sequence(self, seq, **kw): return "<next sequence value: %s>" % self.preparer.format_sequence(seq) def returning_clause(self, stmt, returning_cols): columns = [ self._label_select_column(None, c, True, False, {}) for c in elements._select_iterables(returning_cols) ] return "RETURNING " + ", ".join(columns) def update_from_clause( self, update_stmt, from_table, extra_froms, from_hints, **kw ): return "FROM " + ", ".join( t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw) for t in extra_froms ) def delete_extra_from_clause( self, update_stmt, from_table, extra_froms, from_hints, **kw ): return ", " + ", ".join( t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw) for t in extra_froms ) def get_from_hint_text(self, table, text): return "[%s]" % text class DDLCompiler(Compiled): @util.memoized_property def sql_compiler(self): return self.dialect.statement_compiler( self.dialect, None, schema_translate_map=self.schema_translate_map ) @util.memoized_property def type_compiler(self): return self.dialect.type_compiler def construct_params(self, params=None): return None def visit_ddl(self, ddl, **kwargs): # table events can substitute table and schema name context = ddl.context if isinstance(ddl.target, schema.Table): context = context.copy() preparer = self.preparer path = preparer.format_table_seq(ddl.target) if len(path) == 1: table, sch = path[0], "" else: table, sch = path[-1], path[0] context.setdefault("table", table) context.setdefault("schema", sch) context.setdefault("fullname", preparer.format_table(ddl.target)) return self.sql_compiler.post_process_text(ddl.statement % context) def visit_create_schema(self, create): schema = self.preparer.format_schema(create.element) return "CREATE SCHEMA " + schema def visit_drop_schema(self, drop): schema = self.preparer.format_schema(drop.element) text = "DROP SCHEMA " + schema if drop.cascade: text += " CASCADE" return text def visit_create_table(self, create): table = create.element preparer = self.preparer text = "\nCREATE " if table._prefixes: text += " ".join(table._prefixes) + " " text += "TABLE " + preparer.format_table(table) + " " create_table_suffix = self.create_table_suffix(table) if create_table_suffix: text += create_table_suffix + " " text += "(" separator = "\n" # if only one primary key, specify it along with the column first_pk = False for create_column in create.columns: column = create_column.element try: processed = self.process( create_column, first_pk=column.primary_key and not first_pk ) if processed is not None: text += separator separator = ", \n" text += "\t" + processed if column.primary_key: first_pk = True except exc.CompileError as ce: util.raise_( exc.CompileError( util.u("(in table '%s', column '%s'): %s") % (table.description, column.name, ce.args[0]) ), from_=ce, ) const = self.create_table_constraints( table, _include_foreign_key_constraints=create.include_foreign_key_constraints, # noqa ) if const: text += separator + "\t" + const text += "\n)%s\n\n" % self.post_create_table(table) return text def visit_create_column(self, create, first_pk=False): column = create.element if column.system: return None text = self.get_column_specification(column, first_pk=first_pk) const = " ".join( self.process(constraint) for constraint in column.constraints ) if const: text += " " + const return text def create_table_constraints( self, table, _include_foreign_key_constraints=None ): # On some DB order is significant: visit PK first, then the # other constraints (engine.ReflectionTest.testbasic failed on FB2) constraints = [] if table.primary_key: constraints.append(table.primary_key) all_fkcs = table.foreign_key_constraints if _include_foreign_key_constraints is not None: omit_fkcs = all_fkcs.difference(_include_foreign_key_constraints) else: omit_fkcs = set() constraints.extend( [ c for c in table._sorted_constraints if c is not table.primary_key and c not in omit_fkcs ] ) return ", \n\t".join( p for p in ( self.process(constraint) for constraint in constraints if ( constraint._create_rule is None or constraint._create_rule(self) ) and ( not self.dialect.supports_alter or not getattr(constraint, "use_alter", False) ) ) if p is not None ) def visit_drop_table(self, drop): return "\nDROP TABLE " + self.preparer.format_table(drop.element) def visit_drop_view(self, drop): return "\nDROP VIEW " + self.preparer.format_table(drop.element) def _verify_index_table(self, index): if index.table is None: raise exc.CompileError( "Index '%s' is not associated " "with any table." % index.name ) def visit_create_index( self, create, include_schema=False, include_table_schema=True ): index = create.element self._verify_index_table(index) preparer = self.preparer text = "CREATE " if index.unique: text += "UNIQUE " if index.name is None: raise exc.CompileError( "CREATE INDEX requires that the index have a name" ) text += "INDEX %s ON %s (%s)" % ( self._prepared_index_name(index, include_schema=include_schema), preparer.format_table( index.table, use_schema=include_table_schema ), ", ".join( self.sql_compiler.process( expr, include_table=False, literal_binds=True ) for expr in index.expressions ), ) return text def visit_drop_index(self, drop): index = drop.element if index.name is None: raise exc.CompileError( "DROP INDEX requires that the index have a name" ) return "\nDROP INDEX " + self._prepared_index_name( index, include_schema=True ) def _prepared_index_name(self, index, include_schema=False): if index.table is not None: effective_schema = self.preparer.schema_for_object(index.table) else: effective_schema = None if include_schema and effective_schema: schema_name = self.preparer.quote_schema(effective_schema) else: schema_name = None index_name = self.preparer.format_index(index) if schema_name: index_name = schema_name + "." + index_name return index_name def visit_add_constraint(self, create): return "ALTER TABLE %s ADD %s" % ( self.preparer.format_table(create.element.table), self.process(create.element), ) def visit_set_table_comment(self, create): return "COMMENT ON TABLE %s IS %s" % ( self.preparer.format_table(create.element), self.sql_compiler.render_literal_value( create.element.comment, sqltypes.String() ), ) def visit_drop_table_comment(self, drop): return "COMMENT ON TABLE %s IS NULL" % self.preparer.format_table( drop.element ) def visit_set_column_comment(self, create): return "COMMENT ON COLUMN %s IS %s" % ( self.preparer.format_column( create.element, use_table=True, use_schema=True ), self.sql_compiler.render_literal_value( create.element.comment, sqltypes.String() ), ) def visit_drop_column_comment(self, drop): return "COMMENT ON COLUMN %s IS NULL" % self.preparer.format_column( drop.element, use_table=True ) def visit_create_sequence(self, create): text = "CREATE SEQUENCE %s" % self.preparer.format_sequence( create.element ) if create.element.increment is not None: text += " INCREMENT BY %d" % create.element.increment if create.element.start is not None: text += " START WITH %d" % create.element.start if create.element.minvalue is not None: text += " MINVALUE %d" % create.element.minvalue if create.element.maxvalue is not None: text += " MAXVALUE %d" % create.element.maxvalue if create.element.nominvalue is not None: text += " NO MINVALUE" if create.element.nomaxvalue is not None: text += " NO MAXVALUE" if create.element.cache is not None: text += " CACHE %d" % create.element.cache if create.element.order is True: text += " ORDER" if create.element.cycle is not None: text += " CYCLE" return text def visit_drop_sequence(self, drop): return "DROP SEQUENCE %s" % self.preparer.format_sequence(drop.element) def visit_drop_constraint(self, drop): constraint = drop.element if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) else: formatted_name = None if formatted_name is None: raise exc.CompileError( "Can't emit DROP CONSTRAINT for constraint %r; " "it has no name" % drop.element ) return "ALTER TABLE %s DROP CONSTRAINT %s%s" % ( self.preparer.format_table(drop.element.table), formatted_name, drop.cascade and " CASCADE" or "", ) def get_column_specification(self, column, **kwargs): colspec = ( self.preparer.format_column(column) + " " + self.dialect.type_compiler.process( column.type, type_expression=column ) ) default = self.get_column_default_string(column) if default is not None: colspec += " DEFAULT " + default if column.computed is not None: colspec += " " + self.process(column.computed) if not column.nullable: colspec += " NOT NULL" return colspec def create_table_suffix(self, table): return "" def post_create_table(self, table): return "" def get_column_default_string(self, column): if isinstance(column.server_default, schema.DefaultClause): if isinstance(column.server_default.arg, util.string_types): return self.sql_compiler.render_literal_value( column.server_default.arg, sqltypes.STRINGTYPE ) else: return self.sql_compiler.process( column.server_default.arg, literal_binds=True ) else: return None def visit_check_constraint(self, constraint): text = "" if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) if formatted_name is not None: text += "CONSTRAINT %s " % formatted_name text += "CHECK (%s)" % self.sql_compiler.process( constraint.sqltext, include_table=False, literal_binds=True ) text += self.define_constraint_deferrability(constraint) return text def visit_column_check_constraint(self, constraint): text = "" if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) if formatted_name is not None: text += "CONSTRAINT %s " % formatted_name text += "CHECK (%s)" % self.sql_compiler.process( constraint.sqltext, include_table=False, literal_binds=True ) text += self.define_constraint_deferrability(constraint) return text def visit_primary_key_constraint(self, constraint): if len(constraint) == 0: return "" text = "" if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) if formatted_name is not None: text += "CONSTRAINT %s " % formatted_name text += "PRIMARY KEY " text += "(%s)" % ", ".join( self.preparer.quote(c.name) for c in ( constraint.columns_autoinc_first if constraint._implicit_generated else constraint.columns ) ) text += self.define_constraint_deferrability(constraint) return text def visit_foreign_key_constraint(self, constraint): preparer = self.preparer text = "" if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) if formatted_name is not None: text += "CONSTRAINT %s " % formatted_name remote_table = list(constraint.elements)[0].column.table text += "FOREIGN KEY(%s) REFERENCES %s (%s)" % ( ", ".join( preparer.quote(f.parent.name) for f in constraint.elements ), self.define_constraint_remote_table( constraint, remote_table, preparer ), ", ".join( preparer.quote(f.column.name) for f in constraint.elements ), ) text += self.define_constraint_match(constraint) text += self.define_constraint_cascades(constraint) text += self.define_constraint_deferrability(constraint) return text def define_constraint_remote_table(self, constraint, table, preparer): """Format the remote table clause of a CREATE CONSTRAINT clause.""" return preparer.format_table(table) def visit_unique_constraint(self, constraint): if len(constraint) == 0: return "" text = "" if constraint.name is not None: formatted_name = self.preparer.format_constraint(constraint) if formatted_name is not None: text += "CONSTRAINT %s " % formatted_name text += "UNIQUE (%s)" % ( ", ".join(self.preparer.quote(c.name) for c in constraint) ) text += self.define_constraint_deferrability(constraint) return text def define_constraint_cascades(self, constraint): text = "" if constraint.ondelete is not None: text += " ON DELETE %s" % self.preparer.validate_sql_phrase( constraint.ondelete, FK_ON_DELETE ) if constraint.onupdate is not None: text += " ON UPDATE %s" % self.preparer.validate_sql_phrase( constraint.onupdate, FK_ON_UPDATE ) return text def define_constraint_deferrability(self, constraint): text = "" if constraint.deferrable is not None: if constraint.deferrable: text += " DEFERRABLE" else: text += " NOT DEFERRABLE" if constraint.initially is not None: text += " INITIALLY %s" % self.preparer.validate_sql_phrase( constraint.initially, FK_INITIALLY ) return text def define_constraint_match(self, constraint): text = "" if constraint.match is not None: text += " MATCH %s" % constraint.match return text def visit_computed_column(self, generated): text = "GENERATED ALWAYS AS (%s)" % self.sql_compiler.process( generated.sqltext, include_table=False, literal_binds=True ) if generated.persisted is True: text += " STORED" elif generated.persisted is False: text += " VIRTUAL" return text class GenericTypeCompiler(TypeCompiler): def visit_FLOAT(self, type_, **kw): return "FLOAT" def visit_REAL(self, type_, **kw): return "REAL" def visit_NUMERIC(self, type_, **kw): if type_.precision is None: return "NUMERIC" elif type_.scale is None: return "NUMERIC(%(precision)s)" % {"precision": type_.precision} else: return "NUMERIC(%(precision)s, %(scale)s)" % { "precision": type_.precision, "scale": type_.scale, } def visit_DECIMAL(self, type_, **kw): if type_.precision is None: return "DECIMAL" elif type_.scale is None: return "DECIMAL(%(precision)s)" % {"precision": type_.precision} else: return "DECIMAL(%(precision)s, %(scale)s)" % { "precision": type_.precision, "scale": type_.scale, } def visit_INTEGER(self, type_, **kw): return "INTEGER" def visit_SMALLINT(self, type_, **kw): return "SMALLINT" def visit_BIGINT(self, type_, **kw): return "BIGINT" def visit_TIMESTAMP(self, type_, **kw): return "TIMESTAMP" def visit_DATETIME(self, type_, **kw): return "DATETIME" def visit_DATE(self, type_, **kw): return "DATE" def visit_TIME(self, type_, **kw): return "TIME" def visit_CLOB(self, type_, **kw): return "CLOB" def visit_NCLOB(self, type_, **kw): return "NCLOB" def _render_string_type(self, type_, name): text = name if type_.length: text += "(%d)" % type_.length if type_.collation: text += ' COLLATE "%s"' % type_.collation return text def visit_CHAR(self, type_, **kw): return self._render_string_type(type_, "CHAR") def visit_NCHAR(self, type_, **kw): return self._render_string_type(type_, "NCHAR") def visit_VARCHAR(self, type_, **kw): return self._render_string_type(type_, "VARCHAR") def visit_NVARCHAR(self, type_, **kw): return self._render_string_type(type_, "NVARCHAR") def visit_TEXT(self, type_, **kw): return self._render_string_type(type_, "TEXT") def visit_BLOB(self, type_, **kw): return "BLOB" def visit_BINARY(self, type_, **kw): return "BINARY" + (type_.length and "(%d)" % type_.length or "") def visit_VARBINARY(self, type_, **kw): return "VARBINARY" + (type_.length and "(%d)" % type_.length or "") def visit_BOOLEAN(self, type_, **kw): return "BOOLEAN" def visit_large_binary(self, type_, **kw): return self.visit_BLOB(type_, **kw) def visit_boolean(self, type_, **kw): return self.visit_BOOLEAN(type_, **kw) def visit_time(self, type_, **kw): return self.visit_TIME(type_, **kw) def visit_datetime(self, type_, **kw): return self.visit_DATETIME(type_, **kw) def visit_date(self, type_, **kw): return self.visit_DATE(type_, **kw) def visit_big_integer(self, type_, **kw): return self.visit_BIGINT(type_, **kw) def visit_small_integer(self, type_, **kw): return self.visit_SMALLINT(type_, **kw) def visit_integer(self, type_, **kw): return self.visit_INTEGER(type_, **kw) def visit_real(self, type_, **kw): return self.visit_REAL(type_, **kw) def visit_float(self, type_, **kw): return self.visit_FLOAT(type_, **kw) def visit_numeric(self, type_, **kw): return self.visit_NUMERIC(type_, **kw) def visit_string(self, type_, **kw): return self.visit_VARCHAR(type_, **kw) def visit_unicode(self, type_, **kw): return self.visit_VARCHAR(type_, **kw) def visit_text(self, type_, **kw): return self.visit_TEXT(type_, **kw) def visit_unicode_text(self, type_, **kw): return self.visit_TEXT(type_, **kw) def visit_enum(self, type_, **kw): return self.visit_VARCHAR(type_, **kw) def visit_null(self, type_, **kw): raise exc.CompileError( "Can't generate DDL for %r; " "did you forget to specify a " "type on this Column?" % type_ ) def visit_type_decorator(self, type_, **kw): return self.process(type_.type_engine(self.dialect), **kw) def visit_user_defined(self, type_, **kw): return type_.get_col_spec(**kw) class StrSQLTypeCompiler(GenericTypeCompiler): def __getattr__(self, key): if key.startswith("visit_"): return self._visit_unknown else: raise AttributeError(key) def _visit_unknown(self, type_, **kw): return "%s" % type_.__class__.__name__ class IdentifierPreparer(object): """Handle quoting and case-folding of identifiers based on options.""" reserved_words = RESERVED_WORDS legal_characters = LEGAL_CHARACTERS illegal_initial_characters = ILLEGAL_INITIAL_CHARACTERS schema_for_object = schema._schema_getter(None) def __init__( self, dialect, initial_quote='"', final_quote=None, escape_quote='"', quote_case_sensitive_collations=True, omit_schema=False, ): """Construct a new ``IdentifierPreparer`` object. initial_quote Character that begins a delimited identifier. final_quote Character that ends a delimited identifier. Defaults to `initial_quote`. omit_schema Prevent prepending schema name. Useful for databases that do not support schemae. """ self.dialect = dialect self.initial_quote = initial_quote self.final_quote = final_quote or self.initial_quote self.escape_quote = escape_quote self.escape_to_quote = self.escape_quote * 2 self.omit_schema = omit_schema self.quote_case_sensitive_collations = quote_case_sensitive_collations self._strings = {} self._double_percents = self.dialect.paramstyle in ( "format", "pyformat", ) def _with_schema_translate(self, schema_translate_map): prep = self.__class__.__new__(self.__class__) prep.__dict__.update(self.__dict__) prep.schema_for_object = schema._schema_getter(schema_translate_map) return prep def _escape_identifier(self, value): """Escape an identifier. Subclasses should override this to provide database-dependent escaping behavior. """ value = value.replace(self.escape_quote, self.escape_to_quote) if self._double_percents: value = value.replace("%", "%%") return value def _unescape_identifier(self, value): """Canonicalize an escaped identifier. Subclasses should override this to provide database-dependent unescaping behavior that reverses _escape_identifier. """ return value.replace(self.escape_to_quote, self.escape_quote) def validate_sql_phrase(self, element, reg): """keyword sequence filter. a filter for elements that are intended to represent keyword sequences, such as "INITIALLY", "INITIALLY DEFERRED", etc. no special characters should be present. .. versionadded:: 1.3 """ if element is not None and not reg.match(element): raise exc.CompileError( "Unexpected SQL phrase: %r (matching against %r)" % (element, reg.pattern) ) return element def quote_identifier(self, value): """Quote an identifier. Subclasses should override this to provide database-dependent quoting behavior. """ return ( self.initial_quote + self._escape_identifier(value) + self.final_quote ) def _requires_quotes(self, value): """Return True if the given identifier requires quoting.""" lc_value = value.lower() return ( lc_value in self.reserved_words or value[0] in self.illegal_initial_characters or not self.legal_characters.match(util.text_type(value)) or (lc_value != value) ) def _requires_quotes_illegal_chars(self, value): """Return True if the given identifier requires quoting, but not taking case convention into account.""" return not self.legal_characters.match(util.text_type(value)) def quote_schema(self, schema, force=None): """Conditionally quote a schema name. The name is quoted if it is a reserved word, contains quote-necessary characters, or is an instance of :class:`.quoted_name` which includes ``quote`` set to ``True``. Subclasses can override this to provide database-dependent quoting behavior for schema names. :param schema: string schema name :param force: unused .. deprecated:: 0.9 The :paramref:`.IdentifierPreparer.quote_schema.force` parameter is deprecated and will be removed in a future release. This flag has no effect on the behavior of the :meth:`.IdentifierPreparer.quote` method; please refer to :class:`.quoted_name`. """ if force is not None: # not using the util.deprecated_params() decorator in this # case because of the additional function call overhead on this # very performance-critical spot. util.warn_deprecated( "The IdentifierPreparer.quote_schema.force parameter is " "deprecated and will be removed in a future release. This " "flag has no effect on the behavior of the " "IdentifierPreparer.quote method; please refer to " "quoted_name()." ) return self.quote(schema) def quote(self, ident, force=None): """Conditionally quote an identfier. The identifier is quoted if it is a reserved word, contains quote-necessary characters, or is an instance of :class:`.quoted_name` which includes ``quote`` set to ``True``. Subclasses can override this to provide database-dependent quoting behavior for identifier names. :param ident: string identifier :param force: unused .. deprecated:: 0.9 The :paramref:`.IdentifierPreparer.quote.force` parameter is deprecated and will be removed in a future release. This flag has no effect on the behavior of the :meth:`.IdentifierPreparer.quote` method; please refer to :class:`.quoted_name`. """ if force is not None: # not using the util.deprecated_params() decorator in this # case because of the additional function call overhead on this # very performance-critical spot. util.warn_deprecated( "The IdentifierPreparer.quote.force parameter is " "deprecated and will be removed in a future release. This " "flag has no effect on the behavior of the " "IdentifierPreparer.quote method; please refer to " "quoted_name()." ) force = getattr(ident, "quote", None) if force is None: if ident in self._strings: return self._strings[ident] else: if self._requires_quotes(ident): self._strings[ident] = self.quote_identifier(ident) else: self._strings[ident] = ident return self._strings[ident] elif force: return self.quote_identifier(ident) else: return ident def format_collation(self, collation_name): if self.quote_case_sensitive_collations: return self.quote(collation_name) else: return collation_name def format_sequence(self, sequence, use_schema=True): name = self.quote(sequence.name) effective_schema = self.schema_for_object(sequence) if ( not self.omit_schema and use_schema and effective_schema is not None ): name = self.quote_schema(effective_schema) + "." + name return name def format_label(self, label, name=None): return self.quote(name or label.name) def format_alias(self, alias, name=None): return self.quote(name or alias.name) def format_savepoint(self, savepoint, name=None): # Running the savepoint name through quoting is unnecessary # for all known dialects. This is here to support potential # third party use cases ident = name or savepoint.ident if self._requires_quotes(ident): ident = self.quote_identifier(ident) return ident @util.dependencies("sqlalchemy.sql.naming") def format_constraint(self, naming, constraint): if constraint.name is elements._NONE_NAME: name = naming._constraint_name_for_table( constraint, constraint.table ) if name is None: return None else: name = constraint.name if isinstance(name, elements._truncated_label): # calculate these at format time so that ad-hoc changes # to dialect.max_identifier_length etc. can be reflected # as IdentifierPreparer is long lived if constraint.__visit_name__ == "index": max_ = ( self.dialect.max_index_name_length or self.dialect.max_identifier_length ) else: max_ = ( self.dialect.max_constraint_name_length or self.dialect.max_identifier_length ) if len(name) > max_: name = name[0 : max_ - 8] + "_" + util.md5_hex(name)[-4:] else: self.dialect.validate_identifier(name) return self.quote(name) def format_index(self, index): return self.format_constraint(index) def format_table(self, table, use_schema=True, name=None): """Prepare a quoted table and schema name.""" if name is None: name = table.name result = self.quote(name) effective_schema = self.schema_for_object(table) if not self.omit_schema and use_schema and effective_schema: result = self.quote_schema(effective_schema) + "." + result return result def format_schema(self, name): """Prepare a quoted schema name.""" return self.quote(name) def format_column( self, column, use_table=False, name=None, table_name=None, use_schema=False, ): """Prepare a quoted column name.""" if name is None: name = column.name if not getattr(column, "is_literal", False): if use_table: return ( self.format_table( column.table, use_schema=use_schema, name=table_name ) + "." + self.quote(name) ) else: return self.quote(name) else: # literal textual elements get stuck into ColumnClause a lot, # which shouldn't get quoted if use_table: return ( self.format_table( column.table, use_schema=use_schema, name=table_name ) + "." + name ) else: return name def format_table_seq(self, table, use_schema=True): """Format table name and schema as a tuple.""" # Dialects with more levels in their fully qualified references # ('database', 'owner', etc.) could override this and return # a longer sequence. effective_schema = self.schema_for_object(table) if not self.omit_schema and use_schema and effective_schema: return ( self.quote_schema(effective_schema), self.format_table(table, use_schema=False), ) else: return (self.format_table(table, use_schema=False),) @util.memoized_property def _r_identifiers(self): initial, final, escaped_final = [ re.escape(s) for s in ( self.initial_quote, self.final_quote, self._escape_identifier(self.final_quote), ) ] r = re.compile( r"(?:" r"(?:%(initial)s((?:%(escaped)s|[^%(final)s])+)%(final)s" r"|([^\.]+))(?=\.|$))+" % {"initial": initial, "final": final, "escaped": escaped_final} ) return r def unformat_identifiers(self, identifiers): """Unpack 'schema.table.column'-like strings into components.""" r = self._r_identifiers return [ self._unescape_identifier(i) for i in [a or b for a, b in r.findall(identifiers)] ]