from sqlalchemy import schema as sa_schema, types as sqltypes from sqlalchemy.engine.reflection import Inspector from sqlalchemy import event from ..operations import ops import logging from .. import util from ..util import compat from ..util import sqla_compat from sqlalchemy.util import OrderedSet import re from .render import _user_defined_render import contextlib from alembic.ddl.base import _fk_spec log = logging.getLogger(__name__) def _populate_migration_script(autogen_context, migration_script): upgrade_ops = migration_script.upgrade_ops_list[-1] downgrade_ops = migration_script.downgrade_ops_list[-1] _produce_net_changes(autogen_context, upgrade_ops) upgrade_ops.reverse_into(downgrade_ops) comparators = util.Dispatcher(uselist=True) def _produce_net_changes(autogen_context, upgrade_ops): connection = autogen_context.connection include_schemas = autogen_context.opts.get('include_schemas', False) inspector = Inspector.from_engine(connection) default_schema = connection.dialect.default_schema_name if include_schemas: schemas = set(inspector.get_schema_names()) # replace default schema name with None schemas.discard("information_schema") # replace the "default" schema with None schemas.add(None) schemas.discard(default_schema) else: schemas = [None] comparators.dispatch("schema", autogen_context.dialect.name)( autogen_context, upgrade_ops, schemas ) @comparators.dispatch_for("schema") def _autogen_for_tables(autogen_context, upgrade_ops, schemas): inspector = autogen_context.inspector metadata = autogen_context.metadata conn_table_names = set() version_table_schema = \ autogen_context.migration_context.version_table_schema version_table = autogen_context.migration_context.version_table for s in schemas: tables = set(inspector.get_table_names(schema=s)) if s == version_table_schema: tables = tables.difference( [autogen_context.migration_context.version_table] ) conn_table_names.update(zip([s] * len(tables), tables)) metadata_table_names = OrderedSet( [(table.schema, table.name) for table in metadata.sorted_tables] ).difference([(version_table_schema, version_table)]) _compare_tables(conn_table_names, metadata_table_names, inspector, metadata, upgrade_ops, autogen_context) def _compare_tables(conn_table_names, metadata_table_names, inspector, metadata, upgrade_ops, autogen_context): default_schema = inspector.bind.dialect.default_schema_name # tables coming from the connection will not have "schema" # set if it matches default_schema_name; so we need a list # of table names from local metadata that also have "None" if schema # == default_schema_name. Most setups will be like this anyway but # some are not (see #170) metadata_table_names_no_dflt_schema = OrderedSet([ (schema if schema != default_schema else None, tname) for schema, tname in metadata_table_names ]) # to adjust for the MetaData collection storing the tables either # as "schemaname.tablename" or just "tablename", create a new lookup # which will match the "non-default-schema" keys to the Table object. tname_to_table = dict( ( no_dflt_schema, metadata.tables[sa_schema._get_table_key(tname, schema)] ) for no_dflt_schema, (schema, tname) in zip( metadata_table_names_no_dflt_schema, metadata_table_names) ) metadata_table_names = metadata_table_names_no_dflt_schema for s, tname in metadata_table_names.difference(conn_table_names): name = '%s.%s' % (s, tname) if s else tname metadata_table = tname_to_table[(s, tname)] if autogen_context.run_filters( metadata_table, tname, "table", False, None): upgrade_ops.ops.append( ops.CreateTableOp.from_table(metadata_table)) log.info("Detected added table %r", name) modify_table_ops = ops.ModifyTableOps(tname, [], schema=s) comparators.dispatch("table")( autogen_context, modify_table_ops, s, tname, None, metadata_table ) if not modify_table_ops.is_empty(): upgrade_ops.ops.append(modify_table_ops) removal_metadata = sa_schema.MetaData() for s, tname in conn_table_names.difference(metadata_table_names): name = sa_schema._get_table_key(tname, s) exists = name in removal_metadata.tables t = sa_schema.Table(tname, removal_metadata, schema=s) if not exists: event.listen( t, "column_reflect", autogen_context.migration_context.impl. _compat_autogen_column_reflect(inspector)) inspector.reflecttable(t, None) if autogen_context.run_filters(t, tname, "table", True, None): upgrade_ops.ops.append( ops.DropTableOp.from_table(t) ) log.info("Detected removed table %r", name) existing_tables = conn_table_names.intersection(metadata_table_names) existing_metadata = sa_schema.MetaData() conn_column_info = {} for s, tname in existing_tables: name = sa_schema._get_table_key(tname, s) exists = name in existing_metadata.tables t = sa_schema.Table(tname, existing_metadata, schema=s) if not exists: event.listen( t, "column_reflect", autogen_context.migration_context.impl. _compat_autogen_column_reflect(inspector)) inspector.reflecttable(t, None) conn_column_info[(s, tname)] = t for s, tname in sorted(existing_tables, key=lambda x: (x[0] or '', x[1])): s = s or None name = '%s.%s' % (s, tname) if s else tname metadata_table = tname_to_table[(s, tname)] conn_table = existing_metadata.tables[name] if autogen_context.run_filters( metadata_table, tname, "table", False, conn_table): modify_table_ops = ops.ModifyTableOps(tname, [], schema=s) with _compare_columns( s, tname, conn_table, metadata_table, modify_table_ops, autogen_context, inspector): comparators.dispatch("table")( autogen_context, modify_table_ops, s, tname, conn_table, metadata_table ) if not modify_table_ops.is_empty(): upgrade_ops.ops.append(modify_table_ops) def _make_index(params, conn_table): # TODO: add .info such as 'duplicates_constraint' return sa_schema.Index( params['name'], *[conn_table.c[cname] for cname in params['column_names']], unique=params['unique'] ) def _make_unique_constraint(params, conn_table): # TODO: add .info such as 'duplicates_index' return sa_schema.UniqueConstraint( *[conn_table.c[cname] for cname in params['column_names']], name=params['name'] ) def _make_foreign_key(params, conn_table): tname = params['referred_table'] if params['referred_schema']: tname = "%s.%s" % (params['referred_schema'], tname) options = params.get('options', {}) const = sa_schema.ForeignKeyConstraint( [conn_table.c[cname] for cname in params['constrained_columns']], ["%s.%s" % (tname, n) for n in params['referred_columns']], onupdate=options.get('onupdate'), ondelete=options.get('ondelete'), deferrable=options.get('deferrable'), initially=options.get('initially'), name=params['name'] ) # needed by 0.7 conn_table.append_constraint(const) return const @contextlib.contextmanager def _compare_columns(schema, tname, conn_table, metadata_table, modify_table_ops, autogen_context, inspector): name = '%s.%s' % (schema, tname) if schema else tname metadata_cols_by_name = dict((c.name, c) for c in metadata_table.c) conn_col_names = dict((c.name, c) for c in conn_table.c) metadata_col_names = OrderedSet(sorted(metadata_cols_by_name)) for cname in metadata_col_names.difference(conn_col_names): if autogen_context.run_filters( metadata_cols_by_name[cname], cname, "column", False, None): modify_table_ops.ops.append( ops.AddColumnOp.from_column_and_tablename( schema, tname, metadata_cols_by_name[cname]) ) log.info("Detected added column '%s.%s'", name, cname) for colname in metadata_col_names.intersection(conn_col_names): metadata_col = metadata_cols_by_name[colname] conn_col = conn_table.c[colname] if not autogen_context.run_filters( metadata_col, colname, "column", False, conn_col): continue alter_column_op = ops.AlterColumnOp( tname, colname, schema=schema) comparators.dispatch("column")( autogen_context, alter_column_op, schema, tname, colname, conn_col, metadata_col ) if alter_column_op.has_changes(): modify_table_ops.ops.append(alter_column_op) yield for cname in set(conn_col_names).difference(metadata_col_names): if autogen_context.run_filters( conn_table.c[cname], cname, "column", True, None): modify_table_ops.ops.append( ops.DropColumnOp.from_column_and_tablename( schema, tname, conn_table.c[cname] ) ) log.info("Detected removed column '%s.%s'", name, cname) class _constraint_sig(object): def __eq__(self, other): return self.const == other.const def __ne__(self, other): return self.const != other.const def __hash__(self): return hash(self.const) class _uq_constraint_sig(_constraint_sig): is_index = False is_unique = True def __init__(self, const): self.const = const self.name = const.name self.sig = tuple(sorted([col.name for col in const.columns])) @property def column_names(self): return [col.name for col in self.const.columns] class _ix_constraint_sig(_constraint_sig): is_index = True def __init__(self, const): self.const = const self.name = const.name self.sig = tuple(sorted([col.name for col in const.columns])) self.is_unique = bool(const.unique) @property def column_names(self): return sqla_compat._get_index_column_names(self.const) class _fk_constraint_sig(_constraint_sig): def __init__(self, const, include_options=False): self.const = const self.name = const.name ( self.source_schema, self.source_table, self.source_columns, self.target_schema, self.target_table, self.target_columns, onupdate, ondelete, deferrable, initially) = _fk_spec(const) self.sig = ( self.source_schema, self.source_table, tuple(self.source_columns), self.target_schema, self.target_table, tuple(self.target_columns) ) if include_options: self.sig += ( (None if onupdate.lower() == 'no action' else onupdate.lower()) if onupdate else None, (None if ondelete.lower() == 'no action' else ondelete.lower()) if ondelete else None, # convert initially + deferrable into one three-state value "initially_deferrable" if initially and initially.lower() == "deferred" else "deferrable" if deferrable else "not deferrable" ) @comparators.dispatch_for("table") def _compare_indexes_and_uniques( autogen_context, modify_ops, schema, tname, conn_table, metadata_table): inspector = autogen_context.inspector is_create_table = conn_table is None # 1a. get raw indexes and unique constraints from metadata ... metadata_unique_constraints = set( uq for uq in metadata_table.constraints if isinstance(uq, sa_schema.UniqueConstraint) ) metadata_indexes = set(metadata_table.indexes) conn_uniques = conn_indexes = frozenset() supports_unique_constraints = False if conn_table is not None: # 1b. ... and from connection, if the table exists if hasattr(inspector, "get_unique_constraints"): try: conn_uniques = inspector.get_unique_constraints( tname, schema=schema) supports_unique_constraints = True except NotImplementedError: pass try: conn_indexes = inspector.get_indexes(tname, schema=schema) except NotImplementedError: pass # 2. convert conn-level objects from raw inspector records # into schema objects conn_uniques = set(_make_unique_constraint(uq_def, conn_table) for uq_def in conn_uniques) conn_indexes = set(_make_index(ix, conn_table) for ix in conn_indexes) # 3. give the dialect a chance to omit indexes and constraints that # we know are either added implicitly by the DB or that the DB # can't accurately report on autogen_context.migration_context.impl.\ correct_for_autogen_constraints( conn_uniques, conn_indexes, metadata_unique_constraints, metadata_indexes) # 4. organize the constraints into "signature" collections, the # _constraint_sig() objects provide a consistent facade over both # Index and UniqueConstraint so we can easily work with them # interchangeably metadata_unique_constraints = set(_uq_constraint_sig(uq) for uq in metadata_unique_constraints ) metadata_indexes = set(_ix_constraint_sig(ix) for ix in metadata_indexes) conn_unique_constraints = set( _uq_constraint_sig(uq) for uq in conn_uniques) conn_indexes = set(_ix_constraint_sig(ix) for ix in conn_indexes) # 5. index things by name, for those objects that have names metadata_names = dict( (c.name, c) for c in metadata_unique_constraints.union(metadata_indexes) if c.name is not None) conn_uniques_by_name = dict((c.name, c) for c in conn_unique_constraints) conn_indexes_by_name = dict((c.name, c) for c in conn_indexes) conn_names = dict((c.name, c) for c in conn_unique_constraints.union(conn_indexes) if c.name is not None) doubled_constraints = dict( (name, (conn_uniques_by_name[name], conn_indexes_by_name[name])) for name in set( conn_uniques_by_name).intersection(conn_indexes_by_name) ) # 6. index things by "column signature", to help with unnamed unique # constraints. conn_uniques_by_sig = dict((uq.sig, uq) for uq in conn_unique_constraints) metadata_uniques_by_sig = dict( (uq.sig, uq) for uq in metadata_unique_constraints) metadata_indexes_by_sig = dict( (ix.sig, ix) for ix in metadata_indexes) unnamed_metadata_uniques = dict( (uq.sig, uq) for uq in metadata_unique_constraints if uq.name is None) # assumptions: # 1. a unique constraint or an index from the connection *always* # has a name. # 2. an index on the metadata side *always* has a name. # 3. a unique constraint on the metadata side *might* have a name. # 4. The backend may double up indexes as unique constraints and # vice versa (e.g. MySQL, Postgresql) def obj_added(obj): if obj.is_index: if autogen_context.run_filters( obj.const, obj.name, "index", False, None): modify_ops.ops.append( ops.CreateIndexOp.from_index(obj.const) ) log.info("Detected added index '%s' on %s", obj.name, ', '.join([ "'%s'" % obj.column_names ])) else: if not supports_unique_constraints: # can't report unique indexes as added if we don't # detect them return if is_create_table: # unique constraints are created inline with table defs return if autogen_context.run_filters( obj.const, obj.name, "unique_constraint", False, None): modify_ops.ops.append( ops.AddConstraintOp.from_constraint(obj.const) ) log.info("Detected added unique constraint '%s' on %s", obj.name, ', '.join([ "'%s'" % obj.column_names ])) def obj_removed(obj): if obj.is_index: if obj.is_unique and not supports_unique_constraints: # many databases double up unique constraints # as unique indexes. without that list we can't # be sure what we're doing here return if autogen_context.run_filters( obj.const, obj.name, "index", True, None): modify_ops.ops.append( ops.DropIndexOp.from_index(obj.const) ) log.info( "Detected removed index '%s' on '%s'", obj.name, tname) else: if autogen_context.run_filters( obj.const, obj.name, "unique_constraint", True, None): modify_ops.ops.append( ops.DropConstraintOp.from_constraint(obj.const) ) log.info("Detected removed unique constraint '%s' on '%s'", obj.name, tname ) def obj_changed(old, new, msg): if old.is_index: if autogen_context.run_filters( new.const, new.name, "index", False, old.const): log.info("Detected changed index '%s' on '%s':%s", old.name, tname, ', '.join(msg) ) modify_ops.ops.append( ops.DropIndexOp.from_index(old.const) ) modify_ops.ops.append( ops.CreateIndexOp.from_index(new.const) ) else: if autogen_context.run_filters( new.const, new.name, "unique_constraint", False, old.const): log.info("Detected changed unique constraint '%s' on '%s':%s", old.name, tname, ', '.join(msg) ) modify_ops.ops.append( ops.DropConstraintOp.from_constraint(old.const) ) modify_ops.ops.append( ops.AddConstraintOp.from_constraint(new.const) ) for added_name in sorted(set(metadata_names).difference(conn_names)): obj = metadata_names[added_name] obj_added(obj) for existing_name in sorted(set(metadata_names).intersection(conn_names)): metadata_obj = metadata_names[existing_name] if existing_name in doubled_constraints: conn_uq, conn_idx = doubled_constraints[existing_name] if metadata_obj.is_index: conn_obj = conn_idx else: conn_obj = conn_uq else: conn_obj = conn_names[existing_name] if conn_obj.is_index != metadata_obj.is_index: obj_removed(conn_obj) obj_added(metadata_obj) else: msg = [] if conn_obj.is_unique != metadata_obj.is_unique: msg.append(' unique=%r to unique=%r' % ( conn_obj.is_unique, metadata_obj.is_unique )) if conn_obj.sig != metadata_obj.sig: msg.append(' columns %r to %r' % ( conn_obj.sig, metadata_obj.sig )) if msg: obj_changed(conn_obj, metadata_obj, msg) for removed_name in sorted(set(conn_names).difference(metadata_names)): conn_obj = conn_names[removed_name] if not conn_obj.is_index and conn_obj.sig in unnamed_metadata_uniques: continue elif removed_name in doubled_constraints: if conn_obj.sig not in metadata_indexes_by_sig and \ conn_obj.sig not in metadata_uniques_by_sig: conn_uq, conn_idx = doubled_constraints[removed_name] obj_removed(conn_uq) obj_removed(conn_idx) else: obj_removed(conn_obj) for uq_sig in unnamed_metadata_uniques: if uq_sig not in conn_uniques_by_sig: obj_added(unnamed_metadata_uniques[uq_sig]) @comparators.dispatch_for("column") def _compare_nullable( autogen_context, alter_column_op, schema, tname, cname, conn_col, metadata_col): # work around SQLAlchemy issue #3023 if metadata_col.primary_key: return metadata_col_nullable = metadata_col.nullable conn_col_nullable = conn_col.nullable alter_column_op.existing_nullable = conn_col_nullable if conn_col_nullable is not metadata_col_nullable: alter_column_op.modify_nullable = metadata_col_nullable log.info("Detected %s on column '%s.%s'", "NULL" if metadata_col_nullable else "NOT NULL", tname, cname ) @comparators.dispatch_for("column") def _compare_type( autogen_context, alter_column_op, schema, tname, cname, conn_col, metadata_col): conn_type = conn_col.type alter_column_op.existing_type = conn_type metadata_type = metadata_col.type if conn_type._type_affinity is sqltypes.NullType: log.info("Couldn't determine database type " "for column '%s.%s'", tname, cname) return if metadata_type._type_affinity is sqltypes.NullType: log.info("Column '%s.%s' has no type within " "the model; can't compare", tname, cname) return isdiff = autogen_context.migration_context._compare_type( conn_col, metadata_col) if isdiff: alter_column_op.modify_type = metadata_type log.info("Detected type change from %r to %r on '%s.%s'", conn_type, metadata_type, tname, cname ) def _render_server_default_for_compare(metadata_default, metadata_col, autogen_context): rendered = _user_defined_render( "server_default", metadata_default, autogen_context) if rendered is not False: return rendered if isinstance(metadata_default, sa_schema.DefaultClause): if isinstance(metadata_default.arg, compat.string_types): metadata_default = metadata_default.arg else: metadata_default = str(metadata_default.arg.compile( dialect=autogen_context.dialect)) if isinstance(metadata_default, compat.string_types): if metadata_col.type._type_affinity is sqltypes.String: metadata_default = re.sub(r"^'|'$", "", metadata_default) return repr(metadata_default) else: return metadata_default else: return None @comparators.dispatch_for("column") def _compare_server_default( autogen_context, alter_column_op, schema, tname, cname, conn_col, metadata_col): metadata_default = metadata_col.server_default conn_col_default = conn_col.server_default if conn_col_default is None and metadata_default is None: return False rendered_metadata_default = _render_server_default_for_compare( metadata_default, metadata_col, autogen_context) rendered_conn_default = conn_col.server_default.arg.text \ if conn_col.server_default else None alter_column_op.existing_server_default = conn_col_default isdiff = autogen_context.migration_context._compare_server_default( conn_col, metadata_col, rendered_metadata_default, rendered_conn_default ) if isdiff: alter_column_op.modify_server_default = metadata_default log.info( "Detected server default on column '%s.%s'", tname, cname) @comparators.dispatch_for("table") def _compare_foreign_keys( autogen_context, modify_table_ops, schema, tname, conn_table, metadata_table): # if we're doing CREATE TABLE, all FKs are created # inline within the table def if conn_table is None: return inspector = autogen_context.inspector metadata_fks = set( fk for fk in metadata_table.constraints if isinstance(fk, sa_schema.ForeignKeyConstraint) ) conn_fks = inspector.get_foreign_keys(tname, schema=schema) backend_reflects_fk_options = conn_fks and 'options' in conn_fks[0] conn_fks = set(_make_foreign_key(const, conn_table) for const in conn_fks) # give the dialect a chance to correct the FKs to match more # closely autogen_context.migration_context.impl.\ correct_for_autogen_foreignkeys( conn_fks, metadata_fks, ) metadata_fks = set( _fk_constraint_sig(fk, include_options=backend_reflects_fk_options) for fk in metadata_fks ) conn_fks = set( _fk_constraint_sig(fk, include_options=backend_reflects_fk_options) for fk in conn_fks ) conn_fks_by_sig = dict( (c.sig, c) for c in conn_fks ) metadata_fks_by_sig = dict( (c.sig, c) for c in metadata_fks ) metadata_fks_by_name = dict( (c.name, c) for c in metadata_fks if c.name is not None ) conn_fks_by_name = dict( (c.name, c) for c in conn_fks if c.name is not None ) def _add_fk(obj, compare_to): if autogen_context.run_filters( obj.const, obj.name, "foreign_key_constraint", False, compare_to): modify_table_ops.ops.append( ops.CreateForeignKeyOp.from_constraint(const.const) ) log.info( "Detected added foreign key (%s)(%s) on table %s%s", ", ".join(obj.source_columns), ", ".join(obj.target_columns), "%s." % obj.source_schema if obj.source_schema else "", obj.source_table) def _remove_fk(obj, compare_to): if autogen_context.run_filters( obj.const, obj.name, "foreign_key_constraint", True, compare_to): modify_table_ops.ops.append( ops.DropConstraintOp.from_constraint(obj.const) ) log.info( "Detected removed foreign key (%s)(%s) on table %s%s", ", ".join(obj.source_columns), ", ".join(obj.target_columns), "%s." % obj.source_schema if obj.source_schema else "", obj.source_table) # so far it appears we don't need to do this by name at all. # SQLite doesn't preserve constraint names anyway for removed_sig in set(conn_fks_by_sig).difference(metadata_fks_by_sig): const = conn_fks_by_sig[removed_sig] if removed_sig not in metadata_fks_by_sig: compare_to = metadata_fks_by_name[const.name].const \ if const.name in metadata_fks_by_name else None _remove_fk(const, compare_to) for added_sig in set(metadata_fks_by_sig).difference(conn_fks_by_sig): const = metadata_fks_by_sig[added_sig] if added_sig not in conn_fks_by_sig: compare_to = conn_fks_by_name[const.name].const \ if const.name in conn_fks_by_name else None _add_fk(const, compare_to)