# postgresql/base.py # Copyright (C) 2005-2017 the SQLAlchemy authors and contributors # # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php r""" .. dialect:: postgresql :name: PostgreSQL .. _postgresql_sequences: Sequences/SERIAL ---------------- PostgreSQL supports sequences, and SQLAlchemy uses these as the default means of creating new primary key values for integer-based primary key columns. When creating tables, SQLAlchemy will issue the ``SERIAL`` datatype for integer-based primary key columns, which generates a sequence and server side default corresponding to the column. To specify a specific named sequence to be used for primary key generation, use the :func:`~sqlalchemy.schema.Sequence` construct:: Table('sometable', metadata, Column('id', Integer, Sequence('some_id_seq'), primary_key=True) ) When SQLAlchemy issues a single INSERT statement, to fulfill the contract of having the "last insert identifier" available, a RETURNING clause is added to the INSERT statement which specifies the primary key columns should be returned after the statement completes. The RETURNING functionality only takes place if PostgreSQL 8.2 or later is in use. As a fallback approach, the sequence, whether specified explicitly or implicitly via ``SERIAL``, is executed independently beforehand, the returned value to be used in the subsequent insert. Note that when an :func:`~sqlalchemy.sql.expression.insert()` construct is executed using "executemany" semantics, the "last inserted identifier" functionality does not apply; no RETURNING clause is emitted nor is the sequence pre-executed in this case. To force the usage of RETURNING by default off, specify the flag ``implicit_returning=False`` to :func:`.create_engine`. .. _postgresql_isolation_level: Transaction Isolation Level --------------------------- All PostgreSQL dialects support setting of transaction isolation level both via a dialect-specific parameter :paramref:`.create_engine.isolation_level` accepted by :func:`.create_engine`, as well as the :paramref:`.Connection.execution_options.isolation_level` argument as passed to :meth:`.Connection.execution_options`. When using a non-psycopg2 dialect, this feature works by issuing the command ``SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL `` for each new connection. For the special AUTOCOMMIT isolation level, DBAPI-specific techniques are used. To set isolation level using :func:`.create_engine`:: engine = create_engine( "postgresql+pg8000://scott:tiger@localhost/test", isolation_level="READ UNCOMMITTED" ) To set using per-connection execution options:: connection = engine.connect() connection = connection.execution_options( isolation_level="READ COMMITTED" ) Valid values for ``isolation_level`` include: * ``READ COMMITTED`` * ``READ UNCOMMITTED`` * ``REPEATABLE READ`` * ``SERIALIZABLE`` * ``AUTOCOMMIT`` - on psycopg2 / pg8000 only .. seealso:: :ref:`psycopg2_isolation_level` :ref:`pg8000_isolation_level` .. _postgresql_schema_reflection: Remote-Schema Table Introspection and PostgreSQL search_path ------------------------------------------------------------ The PostgreSQL dialect can reflect tables from any schema. The :paramref:`.Table.schema` argument, or alternatively the :paramref:`.MetaData.reflect.schema` argument determines which schema will be searched for the table or tables. The reflected :class:`.Table` objects will in all cases retain this ``.schema`` attribute as was specified. However, with regards to tables which these :class:`.Table` objects refer to via foreign key constraint, a decision must be made as to how the ``.schema`` is represented in those remote tables, in the case where that remote schema name is also a member of the current `PostgreSQL search path `_. By default, the PostgreSQL dialect mimics the behavior encouraged by PostgreSQL's own ``pg_get_constraintdef()`` builtin procedure. This function returns a sample definition for a particular foreign key constraint, omitting the referenced schema name from that definition when the name is also in the PostgreSQL schema search path. The interaction below illustrates this behavior:: test=> CREATE TABLE test_schema.referred(id INTEGER PRIMARY KEY); CREATE TABLE test=> CREATE TABLE referring( test(> id INTEGER PRIMARY KEY, test(> referred_id INTEGER REFERENCES test_schema.referred(id)); CREATE TABLE test=> SET search_path TO public, test_schema; test=> SELECT pg_catalog.pg_get_constraintdef(r.oid, true) FROM test-> pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n test-> ON n.oid = c.relnamespace test-> JOIN pg_catalog.pg_constraint r ON c.oid = r.conrelid test-> WHERE c.relname='referring' AND r.contype = 'f' test-> ; pg_get_constraintdef --------------------------------------------------- FOREIGN KEY (referred_id) REFERENCES referred(id) (1 row) Above, we created a table ``referred`` as a member of the remote schema ``test_schema``, however when we added ``test_schema`` to the PG ``search_path`` and then asked ``pg_get_constraintdef()`` for the ``FOREIGN KEY`` syntax, ``test_schema`` was not included in the output of the function. On the other hand, if we set the search path back to the typical default of ``public``:: test=> SET search_path TO public; SET The same query against ``pg_get_constraintdef()`` now returns the fully schema-qualified name for us:: test=> SELECT pg_catalog.pg_get_constraintdef(r.oid, true) FROM test-> pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n test-> ON n.oid = c.relnamespace test-> JOIN pg_catalog.pg_constraint r ON c.oid = r.conrelid test-> WHERE c.relname='referring' AND r.contype = 'f'; pg_get_constraintdef --------------------------------------------------------------- FOREIGN KEY (referred_id) REFERENCES test_schema.referred(id) (1 row) SQLAlchemy will by default use the return value of ``pg_get_constraintdef()`` in order to determine the remote schema name. That is, if our ``search_path`` were set to include ``test_schema``, and we invoked a table reflection process as follows:: >>> from sqlalchemy import Table, MetaData, create_engine >>> engine = create_engine("postgresql://scott:tiger@localhost/test") >>> with engine.connect() as conn: ... conn.execute("SET search_path TO test_schema, public") ... meta = MetaData() ... referring = Table('referring', meta, ... autoload=True, autoload_with=conn) ... The above process would deliver to the :attr:`.MetaData.tables` collection ``referred`` table named **without** the schema:: >>> meta.tables['referred'].schema is None True To alter the behavior of reflection such that the referred schema is maintained regardless of the ``search_path`` setting, use the ``postgresql_ignore_search_path`` option, which can be specified as a dialect-specific argument to both :class:`.Table` as well as :meth:`.MetaData.reflect`:: >>> with engine.connect() as conn: ... conn.execute("SET search_path TO test_schema, public") ... meta = MetaData() ... referring = Table('referring', meta, autoload=True, ... autoload_with=conn, ... postgresql_ignore_search_path=True) ... We will now have ``test_schema.referred`` stored as schema-qualified:: >>> meta.tables['test_schema.referred'].schema 'test_schema' .. sidebar:: Best Practices for PostgreSQL Schema reflection The description of PostgreSQL schema reflection behavior is complex, and is the product of many years of dealing with widely varied use cases and user preferences. But in fact, there's no need to understand any of it if you just stick to the simplest use pattern: leave the ``search_path`` set to its default of ``public`` only, never refer to the name ``public`` as an explicit schema name otherwise, and refer to all other schema names explicitly when building up a :class:`.Table` object. The options described here are only for those users who can't, or prefer not to, stay within these guidelines. Note that **in all cases**, the "default" schema is always reflected as ``None``. The "default" schema on PostgreSQL is that which is returned by the PostgreSQL ``current_schema()`` function. On a typical PostgreSQL installation, this is the name ``public``. So a table that refers to another which is in the ``public`` (i.e. default) schema will always have the ``.schema`` attribute set to ``None``. .. versionadded:: 0.9.2 Added the ``postgresql_ignore_search_path`` dialect-level option accepted by :class:`.Table` and :meth:`.MetaData.reflect`. .. seealso:: `The Schema Search Path `_ - on the PostgreSQL website. INSERT/UPDATE...RETURNING ------------------------- The dialect supports PG 8.2's ``INSERT..RETURNING``, ``UPDATE..RETURNING`` and ``DELETE..RETURNING`` syntaxes. ``INSERT..RETURNING`` is used by default for single-row INSERT statements in order to fetch newly generated primary key identifiers. To specify an explicit ``RETURNING`` clause, use the :meth:`._UpdateBase.returning` method on a per-statement basis:: # INSERT..RETURNING result = table.insert().returning(table.c.col1, table.c.col2).\ values(name='foo') print result.fetchall() # UPDATE..RETURNING result = table.update().returning(table.c.col1, table.c.col2).\ where(table.c.name=='foo').values(name='bar') print result.fetchall() # DELETE..RETURNING result = table.delete().returning(table.c.col1, table.c.col2).\ where(table.c.name=='foo') print result.fetchall() .. _postgresql_insert_on_conflict: INSERT...ON CONFLICT (Upsert) ------------------------------ Starting with version 9.5, PostgreSQL allows "upserts" (update or insert) of rows into a table via the ``ON CONFLICT`` clause of the ``INSERT`` statement. A candidate row will only be inserted if that row does not violate any unique constraints. In the case of a unique constraint violation, a secondary action can occur which can be either "DO UPDATE", indicating that the data in the target row should be updated, or "DO NOTHING", which indicates to silently skip this row. Conflicts are determined using existing unique constraints and indexes. These constraints may be identified either using their name as stated in DDL, or they may be *inferred* by stating the columns and conditions that comprise the indexes. SQLAlchemy provides ``ON CONFLICT`` support via the PostgreSQL-specific :func:`.postgresql.dml.insert()` function, which provides the generative methods :meth:`~.postgresql.dml.Insert.on_conflict_do_update` and :meth:`~.postgresql.dml.Insert.on_conflict_do_nothing`:: from sqlalchemy.dialects.postgresql import insert insert_stmt = insert(my_table).values( id='some_existing_id', data='inserted value') do_nothing_stmt = insert_stmt.on_conflict_do_nothing( index_elements=['id'] ) conn.execute(do_nothing_stmt) do_update_stmt = insert_stmt.on_conflict_do_update( constraint='pk_my_table', set_=dict(data='updated value') ) conn.execute(do_update_stmt) Both methods supply the "target" of the conflict using either the named constraint or by column inference: * The :paramref:`.Insert.on_conflict_do_update.index_elements` argument specifies a sequence containing string column names, :class:`.Column` objects, and/or SQL expression elements, which would identify a unique index:: do_update_stmt = insert_stmt.on_conflict_do_update( index_elements=['id'], set_=dict(data='updated value') ) do_update_stmt = insert_stmt.on_conflict_do_update( index_elements=[my_table.c.id], set_=dict(data='updated value') ) * When using :paramref:`.Insert.on_conflict_do_update.index_elements` to infer an index, a partial index can be inferred by also specifying the use the :paramref:`.Insert.on_conflict_do_update.index_where` parameter:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values(user_email='a@b.com', data='inserted data') stmt = stmt.on_conflict_do_update( index_elements=[my_table.c.user_email], index_where=my_table.c.user_email.like('%@gmail.com'), set_=dict(data=stmt.excluded.data) ) conn.execute(stmt) * The :paramref:`.Insert.on_conflict_do_update.constraint` argument is used to specify an index directly rather than inferring it. This can be the name of a UNIQUE constraint, a PRIMARY KEY constraint, or an INDEX:: do_update_stmt = insert_stmt.on_conflict_do_update( constraint='my_table_idx_1', set_=dict(data='updated value') ) do_update_stmt = insert_stmt.on_conflict_do_update( constraint='my_table_pk', set_=dict(data='updated value') ) * The :paramref:`.Insert.on_conflict_do_update.constraint` argument may also refer to a SQLAlchemy construct representing a constraint, e.g. :class:`.UniqueConstraint`, :class:`.PrimaryKeyConstraint`, :class:`.Index`, or :class:`.ExcludeConstraint`. In this use, if the constraint has a name, it is used directly. Otherwise, if the constraint is unnamed, then inference will be used, where the expressions and optional WHERE clause of the constraint will be spelled out in the construct. This use is especially convenient to refer to the named or unnamed primary key of a :class:`.Table` using the :attr:`.Table.primary_key` attribute:: do_update_stmt = insert_stmt.on_conflict_do_update( constraint=my_table.primary_key, set_=dict(data='updated value') ) ``ON CONFLICT...DO UPDATE`` is used to perform an update of the already existing row, using any combination of new values as well as values from the proposed insertion. These values are specified using the :paramref:`.Insert.on_conflict_do_update.set_` parameter. This parameter accepts a dictionary which consists of direct values for UPDATE:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values(id='some_id', data='inserted value') do_update_stmt = stmt.on_conflict_do_update( index_elements=['id'], set_=dict(data='updated value') ) conn.execute(do_update_stmt) .. warning:: The :meth:`.Insert.on_conflict_do_update` method does **not** take into account Python-side default UPDATE values or generation functions, e.g. e.g. those specified using :paramref:`.Column.onupdate`. These values will not be exercised for an ON CONFLICT style of UPDATE, unless they are manually specified in the :paramref:`.Insert.on_conflict_do_update.set_` dictionary. In order to refer to the proposed insertion row, the special alias :attr:`~.postgresql.dml.Insert.excluded` is available as an attribute on the :class:`.postgresql.dml.Insert` object; this object is a :class:`.ColumnCollection` which alias contains all columns of the target table:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values( id='some_id', data='inserted value', author='jlh') do_update_stmt = stmt.on_conflict_do_update( index_elements=['id'], set_=dict(data='updated value', author=stmt.excluded.author) ) conn.execute(do_update_stmt) The :meth:`.Insert.on_conflict_do_update` method also accepts a WHERE clause using the :paramref:`.Insert.on_conflict_do_update.where` parameter, which will limit those rows which receive an UPDATE:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values( id='some_id', data='inserted value', author='jlh') on_update_stmt = stmt.on_conflict_do_update( index_elements=['id'], set_=dict(data='updated value', author=stmt.excluded.author) where=(my_table.c.status == 2) ) conn.execute(on_update_stmt) ``ON CONFLICT`` may also be used to skip inserting a row entirely if any conflict with a unique or exclusion constraint occurs; below this is illustrated using the :meth:`~.postgresql.dml.Insert.on_conflict_do_nothing` method:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values(id='some_id', data='inserted value') stmt = stmt.on_conflict_do_nothing(index_elements=['id']) conn.execute(stmt) If ``DO NOTHING`` is used without specifying any columns or constraint, it has the effect of skipping the INSERT for any unique or exclusion constraint violation which occurs:: from sqlalchemy.dialects.postgresql import insert stmt = insert(my_table).values(id='some_id', data='inserted value') stmt = stmt.on_conflict_do_nothing() conn.execute(stmt) .. versionadded:: 1.1 Added support for PostgreSQL ON CONFLICT clauses .. seealso:: `INSERT .. ON CONFLICT `_ - in the PostgreSQL documentation. .. _postgresql_match: Full Text Search ---------------- SQLAlchemy makes available the PostgreSQL ``@@`` operator via the :meth:`.ColumnElement.match` method on any textual column expression. On a PostgreSQL dialect, an expression like the following:: select([sometable.c.text.match("search string")]) will emit to the database:: SELECT text @@ to_tsquery('search string') FROM table The PostgreSQL text search functions such as ``to_tsquery()`` and ``to_tsvector()`` are available explicitly using the standard :data:`.func` construct. For example:: select([ func.to_tsvector('fat cats ate rats').match('cat & rat') ]) Emits the equivalent of:: SELECT to_tsvector('fat cats ate rats') @@ to_tsquery('cat & rat') The :class:`.postgresql.TSVECTOR` type can provide for explicit CAST:: from sqlalchemy.dialects.postgresql import TSVECTOR from sqlalchemy import select, cast select([cast("some text", TSVECTOR)]) produces a statement equivalent to:: SELECT CAST('some text' AS TSVECTOR) AS anon_1 Full Text Searches in PostgreSQL are influenced by a combination of: the PostgresSQL setting of ``default_text_search_config``, the ``regconfig`` used to build the GIN/GiST indexes, and the ``regconfig`` optionally passed in during a query. When performing a Full Text Search against a column that has a GIN or GiST index that is already pre-computed (which is common on full text searches) one may need to explicitly pass in a particular PostgresSQL ``regconfig`` value to ensure the query-planner utilizes the index and does not re-compute the column on demand. In order to provide for this explicit query planning, or to use different search strategies, the ``match`` method accepts a ``postgresql_regconfig`` keyword argument:: select([mytable.c.id]).where( mytable.c.title.match('somestring', postgresql_regconfig='english') ) Emits the equivalent of:: SELECT mytable.id FROM mytable WHERE mytable.title @@ to_tsquery('english', 'somestring') One can also specifically pass in a `'regconfig'` value to the ``to_tsvector()`` command as the initial argument:: select([mytable.c.id]).where( func.to_tsvector('english', mytable.c.title )\ .match('somestring', postgresql_regconfig='english') ) produces a statement equivalent to:: SELECT mytable.id FROM mytable WHERE to_tsvector('english', mytable.title) @@ to_tsquery('english', 'somestring') It is recommended that you use the ``EXPLAIN ANALYZE...`` tool from PostgresSQL to ensure that you are generating queries with SQLAlchemy that take full advantage of any indexes you may have created for full text search. FROM ONLY ... ------------------------ The dialect supports PostgreSQL's ONLY keyword for targeting only a particular table in an inheritance hierarchy. This can be used to produce the ``SELECT ... FROM ONLY``, ``UPDATE ONLY ...``, and ``DELETE FROM ONLY ...`` syntaxes. It uses SQLAlchemy's hints mechanism:: # SELECT ... FROM ONLY ... result = table.select().with_hint(table, 'ONLY', 'postgresql') print result.fetchall() # UPDATE ONLY ... table.update(values=dict(foo='bar')).with_hint('ONLY', dialect_name='postgresql') # DELETE FROM ONLY ... table.delete().with_hint('ONLY', dialect_name='postgresql') .. _postgresql_indexes: PostgreSQL-Specific Index Options --------------------------------- Several extensions to the :class:`.Index` construct are available, specific to the PostgreSQL dialect. .. _postgresql_partial_indexes: Partial Indexes ^^^^^^^^^^^^^^^^ Partial indexes add criterion to the index definition so that the index is applied to a subset of rows. These can be specified on :class:`.Index` using the ``postgresql_where`` keyword argument:: Index('my_index', my_table.c.id, postgresql_where=my_table.c.value > 10) Operator Classes ^^^^^^^^^^^^^^^^^ PostgreSQL allows the specification of an *operator class* for each column of an index (see http://www.postgresql.org/docs/8.3/interactive/indexes-opclass.html). The :class:`.Index` construct allows these to be specified via the ``postgresql_ops`` keyword argument:: Index('my_index', my_table.c.id, my_table.c.data, postgresql_ops={ 'data': 'text_pattern_ops', 'id': 'int4_ops' }) .. versionadded:: 0.7.2 ``postgresql_ops`` keyword argument to :class:`.Index` construct. Note that the keys in the ``postgresql_ops`` dictionary are the "key" name of the :class:`.Column`, i.e. the name used to access it from the ``.c`` collection of :class:`.Table`, which can be configured to be different than the actual name of the column as expressed in the database. Index Types ^^^^^^^^^^^^ PostgreSQL provides several index types: B-Tree, Hash, GiST, and GIN, as well as the ability for users to create their own (see http://www.postgresql.org/docs/8.3/static/indexes-types.html). These can be specified on :class:`.Index` using the ``postgresql_using`` keyword argument:: Index('my_index', my_table.c.data, postgresql_using='gin') The value passed to the keyword argument will be simply passed through to the underlying CREATE INDEX command, so it *must* be a valid index type for your version of PostgreSQL. .. _postgresql_index_storage: Index Storage Parameters ^^^^^^^^^^^^^^^^^^^^^^^^ PostgreSQL allows storage parameters to be set on indexes. The storage parameters available depend on the index method used by the index. Storage parameters can be specified on :class:`.Index` using the ``postgresql_with`` keyword argument:: Index('my_index', my_table.c.data, postgresql_with={"fillfactor": 50}) .. versionadded:: 1.0.6 PostgreSQL allows to define the tablespace in which to create the index. The tablespace can be specified on :class:`.Index` using the ``postgresql_tablespace`` keyword argument:: Index('my_index', my_table.c.data, postgresql_tablespace='my_tablespace') .. versionadded:: 1.1 Note that the same option is available on :class:`.Table` as well. .. _postgresql_index_concurrently: Indexes with CONCURRENTLY ^^^^^^^^^^^^^^^^^^^^^^^^^ The PostgreSQL index option CONCURRENTLY is supported by passing the flag ``postgresql_concurrently`` to the :class:`.Index` construct:: tbl = Table('testtbl', m, Column('data', Integer)) idx1 = Index('test_idx1', tbl.c.data, postgresql_concurrently=True) The above index construct will render DDL for CREATE INDEX, assuming PostgreSQL 8.2 or higher is detected or for a connection-less dialect, as:: CREATE INDEX CONCURRENTLY test_idx1 ON testtbl (data) For DROP INDEX, assuming PostgreSQL 9.2 or higher is detected or for a connection-less dialect, it will emit:: DROP INDEX CONCURRENTLY test_idx1 .. versionadded:: 1.1 support for CONCURRENTLY on DROP INDEX. The CONCURRENTLY keyword is now only emitted if a high enough version of PostgreSQL is detected on the connection (or for a connection-less dialect). When using CONCURRENTLY, the Postgresql database requires that the statement be invoked outside of a transaction block. The Python DBAPI enforces that even for a single statement, a transaction is present, so to use this construct, the DBAPI's "autocommit" mode must be used:: metadata = MetaData() table = Table( "foo", metadata, Column("id", String)) index = Index( "foo_idx", table.c.id, postgresql_concurrently=True) with engine.connect() as conn: with conn.execution_options(isolation_level='AUTOCOMMIT'): table.create(conn) .. seealso:: :ref:`postgresql_isolation_level` .. _postgresql_index_reflection: PostgreSQL Index Reflection --------------------------- The PostgreSQL database creates a UNIQUE INDEX implicitly whenever the UNIQUE CONSTRAINT construct is used. When inspecting a table using :class:`.Inspector`, the :meth:`.Inspector.get_indexes` and the :meth:`.Inspector.get_unique_constraints` will report on these two constructs distinctly; in the case of the index, the key ``duplicates_constraint`` will be present in the index entry if it is detected as mirroring a constraint. When performing reflection using ``Table(..., autoload=True)``, the UNIQUE INDEX is **not** returned in :attr:`.Table.indexes` when it is detected as mirroring a :class:`.UniqueConstraint` in the :attr:`.Table.constraints` collection. .. versionchanged:: 1.0.0 - :class:`.Table` reflection now includes :class:`.UniqueConstraint` objects present in the :attr:`.Table.constraints` collection; the PostgreSQL backend will no longer include a "mirrored" :class:`.Index` construct in :attr:`.Table.indexes` if it is detected as corresponding to a unique constraint. Special Reflection Options -------------------------- The :class:`.Inspector` used for the PostgreSQL backend is an instance of :class:`.PGInspector`, which offers additional methods:: from sqlalchemy import create_engine, inspect engine = create_engine("postgresql+psycopg2://localhost/test") insp = inspect(engine) # will be a PGInspector print(insp.get_enums()) .. autoclass:: PGInspector :members: .. _postgresql_table_options: PostgreSQL Table Options ------------------------- Several options for CREATE TABLE are supported directly by the PostgreSQL dialect in conjunction with the :class:`.Table` construct: * ``TABLESPACE``:: Table("some_table", metadata, ..., postgresql_tablespace='some_tablespace') The above option is also available on the :class:`.Index` construct. * ``ON COMMIT``:: Table("some_table", metadata, ..., postgresql_on_commit='PRESERVE ROWS') * ``WITH OIDS``:: Table("some_table", metadata, ..., postgresql_with_oids=True) * ``WITHOUT OIDS``:: Table("some_table", metadata, ..., postgresql_with_oids=False) * ``INHERITS``:: Table("some_table", metadata, ..., postgresql_inherits="some_supertable") Table("some_table", metadata, ..., postgresql_inherits=("t1", "t2", ...)) .. versionadded:: 1.0.0 .. seealso:: `PostgreSQL CREATE TABLE options `_ ARRAY Types ----------- The PostgreSQL dialect supports arrays, both as multidimensional column types as well as array literals: * :class:`.postgresql.ARRAY` - ARRAY datatype * :class:`.postgresql.array` - array literal * :func:`.postgresql.array_agg` - ARRAY_AGG SQL function * :class:`.postgresql.aggregate_order_by` - helper for PG's ORDER BY aggregate function syntax. JSON Types ---------- The PostgreSQL dialect supports both JSON and JSONB datatypes, including psycopg2's native support and support for all of PostgreSQL's special operators: * :class:`.postgresql.JSON` * :class:`.postgresql.JSONB` HSTORE Type ----------- The PostgreSQL HSTORE type as well as hstore literals are supported: * :class:`.postgresql.HSTORE` - HSTORE datatype * :class:`.postgresql.hstore` - hstore literal ENUM Types ---------- PostgreSQL has an independently creatable TYPE structure which is used to implement an enumerated type. This approach introduces significant complexity on the SQLAlchemy side in terms of when this type should be CREATED and DROPPED. The type object is also an independently reflectable entity. The following sections should be consulted: * :class:`.postgresql.ENUM` - DDL and typing support for ENUM. * :meth:`.PGInspector.get_enums` - retrieve a listing of current ENUM types * :meth:`.postgresql.ENUM.create` , :meth:`.postgresql.ENUM.drop` - individual CREATE and DROP commands for ENUM. .. _postgresql_array_of_enum: Using ENUM with ARRAY ^^^^^^^^^^^^^^^^^^^^^ The combination of ENUM and ARRAY is not directly supported by backend DBAPIs at this time. In order to send and receive an ARRAY of ENUM, use the following workaround type:: class ArrayOfEnum(ARRAY): def bind_expression(self, bindvalue): return sa.cast(bindvalue, self) def result_processor(self, dialect, coltype): super_rp = super(ArrayOfEnum, self).result_processor( dialect, coltype) def handle_raw_string(value): inner = re.match(r"^{(.*)}$", value).group(1) return inner.split(",") if inner else [] def process(value): if value is None: return None return super_rp(handle_raw_string(value)) return process E.g.:: Table( 'mydata', metadata, Column('id', Integer, primary_key=True), Column('data', ArrayOfEnum(ENUM('a', 'b, 'c', name='myenum'))) ) This type is not included as a built-in type as it would be incompatible with a DBAPI that suddenly decides to support ARRAY of ENUM directly in a new version. .. _postgresql_array_of_json: Using JSON/JSONB with ARRAY ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Similar to using ENUM, for an ARRAY of JSON/JSONB we need to render the appropriate CAST, however current psycopg2 drivers seem to handle the result for ARRAY of JSON automatically, so the type is simpler:: class CastingArray(ARRAY): def bind_expression(self, bindvalue): return sa.cast(bindvalue, self) E.g.:: Table( 'mydata', metadata, Column('id', Integer, primary_key=True), Column('data', CastingArray(JSONB)) ) """ from collections import defaultdict import re import datetime as dt from sqlalchemy.sql import elements from ... import sql, schema, exc, util from ...engine import default, reflection from ...sql import compiler, expression from ... import types as sqltypes try: from uuid import UUID as _python_UUID except ImportError: _python_UUID = None from sqlalchemy.types import INTEGER, BIGINT, SMALLINT, VARCHAR, \ CHAR, TEXT, FLOAT, NUMERIC, \ DATE, BOOLEAN, REAL AUTOCOMMIT_REGEXP = re.compile( r'\s*(?:UPDATE|INSERT|CREATE|DELETE|DROP|ALTER|' 'IMPORT FOREIGN SCHEMA|REFRESH MATERIALIZED VIEW)', re.I | re.UNICODE) RESERVED_WORDS = set( ["all", "analyse", "analyze", "and", "any", "array", "as", "asc", "asymmetric", "both", "case", "cast", "check", "collate", "column", "constraint", "create", "current_catalog", "current_date", "current_role", "current_time", "current_timestamp", "current_user", "default", "deferrable", "desc", "distinct", "do", "else", "end", "except", "false", "fetch", "for", "foreign", "from", "grant", "group", "having", "in", "initially", "intersect", "into", "leading", "limit", "localtime", "localtimestamp", "new", "not", "null", "of", "off", "offset", "old", "on", "only", "or", "order", "placing", "primary", "references", "returning", "select", "session_user", "some", "symmetric", "table", "then", "to", "trailing", "true", "union", "unique", "user", "using", "variadic", "when", "where", "window", "with", "authorization", "between", "binary", "cross", "current_schema", "freeze", "full", "ilike", "inner", "is", "isnull", "join", "left", "like", "natural", "notnull", "outer", "over", "overlaps", "right", "similar", "verbose" ]) _DECIMAL_TYPES = (1231, 1700) _FLOAT_TYPES = (700, 701, 1021, 1022) _INT_TYPES = (20, 21, 23, 26, 1005, 1007, 1016) class BYTEA(sqltypes.LargeBinary): __visit_name__ = 'BYTEA' class DOUBLE_PRECISION(sqltypes.Float): __visit_name__ = 'DOUBLE_PRECISION' class INET(sqltypes.TypeEngine): __visit_name__ = "INET" PGInet = INET class CIDR(sqltypes.TypeEngine): __visit_name__ = "CIDR" PGCidr = CIDR class MACADDR(sqltypes.TypeEngine): __visit_name__ = "MACADDR" PGMacAddr = MACADDR class OID(sqltypes.TypeEngine): """Provide the PostgreSQL OID type. .. versionadded:: 0.9.5 """ __visit_name__ = "OID" class TIMESTAMP(sqltypes.TIMESTAMP): def __init__(self, timezone=False, precision=None): super(TIMESTAMP, self).__init__(timezone=timezone) self.precision = precision class TIME(sqltypes.TIME): def __init__(self, timezone=False, precision=None): super(TIME, self).__init__(timezone=timezone) self.precision = precision class INTERVAL(sqltypes.TypeEngine): """PostgreSQL INTERVAL type. The INTERVAL type may not be supported on all DBAPIs. It is known to work on psycopg2 and not pg8000 or zxjdbc. """ __visit_name__ = 'INTERVAL' def __init__(self, precision=None): self.precision = precision @classmethod def _adapt_from_generic_interval(cls, interval): return INTERVAL(precision=interval.second_precision) @property def _type_affinity(self): return sqltypes.Interval @property def python_type(self): return dt.timedelta PGInterval = INTERVAL class BIT(sqltypes.TypeEngine): __visit_name__ = 'BIT' def __init__(self, length=None, varying=False): if not varying: # BIT without VARYING defaults to length 1 self.length = length or 1 else: # but BIT VARYING can be unlimited-length, so no default self.length = length self.varying = varying PGBit = BIT class UUID(sqltypes.TypeEngine): """PostgreSQL UUID type. Represents the UUID column type, interpreting data either as natively returned by the DBAPI or as Python uuid objects. The UUID type may not be supported on all DBAPIs. It is known to work on psycopg2 and not pg8000. """ __visit_name__ = 'UUID' def __init__(self, as_uuid=False): """Construct a UUID type. :param as_uuid=False: if True, values will be interpreted as Python uuid objects, converting to/from string via the DBAPI. """ if as_uuid and _python_UUID is None: raise NotImplementedError( "This version of Python does not support " "the native UUID type." ) self.as_uuid = as_uuid def bind_processor(self, dialect): if self.as_uuid: def process(value): if value is not None: value = util.text_type(value) return value return process else: return None def result_processor(self, dialect, coltype): if self.as_uuid: def process(value): if value is not None: value = _python_UUID(value) return value return process else: return None PGUuid = UUID class TSVECTOR(sqltypes.TypeEngine): """The :class:`.postgresql.TSVECTOR` type implements the PostgreSQL text search type TSVECTOR. It can be used to do full text queries on natural language documents. .. versionadded:: 0.9.0 .. seealso:: :ref:`postgresql_match` """ __visit_name__ = 'TSVECTOR' class ENUM(sqltypes.Enum): """PostgreSQL ENUM type. This is a subclass of :class:`.types.Enum` which includes support for PG's ``CREATE TYPE`` and ``DROP TYPE``. When the builtin type :class:`.types.Enum` is used and the :paramref:`.Enum.native_enum` flag is left at its default of True, the PostgreSQL backend will use a :class:`.postgresql.ENUM` type as the implementation, so the special create/drop rules will be used. The create/drop behavior of ENUM is necessarily intricate, due to the awkward relationship the ENUM type has in relationship to the parent table, in that it may be "owned" by just a single table, or may be shared among many tables. When using :class:`.types.Enum` or :class:`.postgresql.ENUM` in an "inline" fashion, the ``CREATE TYPE`` and ``DROP TYPE`` is emitted corresponding to when the :meth:`.Table.create` and :meth:`.Table.drop` methods are called:: table = Table('sometable', metadata, Column('some_enum', ENUM('a', 'b', 'c', name='myenum')) ) table.create(engine) # will emit CREATE ENUM and CREATE TABLE table.drop(engine) # will emit DROP TABLE and DROP ENUM To use a common enumerated type between multiple tables, the best practice is to declare the :class:`.types.Enum` or :class:`.postgresql.ENUM` independently, and associate it with the :class:`.MetaData` object itself:: my_enum = ENUM('a', 'b', 'c', name='myenum', metadata=metadata) t1 = Table('sometable_one', metadata, Column('some_enum', myenum) ) t2 = Table('sometable_two', metadata, Column('some_enum', myenum) ) When this pattern is used, care must still be taken at the level of individual table creates. Emitting CREATE TABLE without also specifying ``checkfirst=True`` will still cause issues:: t1.create(engine) # will fail: no such type 'myenum' If we specify ``checkfirst=True``, the individual table-level create operation will check for the ``ENUM`` and create if not exists:: # will check if enum exists, and emit CREATE TYPE if not t1.create(engine, checkfirst=True) When using a metadata-level ENUM type, the type will always be created and dropped if either the metadata-wide create/drop is called:: metadata.create_all(engine) # will emit CREATE TYPE metadata.drop_all(engine) # will emit DROP TYPE The type can also be created and dropped directly:: my_enum.create(engine) my_enum.drop(engine) .. versionchanged:: 1.0.0 The PostgreSQL :class:`.postgresql.ENUM` type now behaves more strictly with regards to CREATE/DROP. A metadata-level ENUM type will only be created and dropped at the metadata level, not the table level, with the exception of ``table.create(checkfirst=True)``. The ``table.drop()`` call will now emit a DROP TYPE for a table-level enumerated type. """ def __init__(self, *enums, **kw): """Construct an :class:`~.postgresql.ENUM`. Arguments are the same as that of :class:`.types.Enum`, but also including the following parameters. :param create_type: Defaults to True. Indicates that ``CREATE TYPE`` should be emitted, after optionally checking for the presence of the type, when the parent table is being created; and additionally that ``DROP TYPE`` is called when the table is dropped. When ``False``, no check will be performed and no ``CREATE TYPE`` or ``DROP TYPE`` is emitted, unless :meth:`~.postgresql.ENUM.create` or :meth:`~.postgresql.ENUM.drop` are called directly. Setting to ``False`` is helpful when invoking a creation scheme to a SQL file without access to the actual database - the :meth:`~.postgresql.ENUM.create` and :meth:`~.postgresql.ENUM.drop` methods can be used to emit SQL to a target bind. .. versionadded:: 0.7.4 """ self.create_type = kw.pop("create_type", True) super(ENUM, self).__init__(*enums, **kw) def create(self, bind=None, checkfirst=True): """Emit ``CREATE TYPE`` for this :class:`~.postgresql.ENUM`. If the underlying dialect does not support PostgreSQL CREATE TYPE, no action is taken. :param bind: a connectable :class:`.Engine`, :class:`.Connection`, or similar object to emit SQL. :param checkfirst: if ``True``, a query against the PG catalog will be first performed to see if the type does not exist already before creating. """ if not bind.dialect.supports_native_enum: return if not checkfirst or \ not bind.dialect.has_type( bind, self.name, schema=self.schema): bind.execute(CreateEnumType(self)) def drop(self, bind=None, checkfirst=True): """Emit ``DROP TYPE`` for this :class:`~.postgresql.ENUM`. If the underlying dialect does not support PostgreSQL DROP TYPE, no action is taken. :param bind: a connectable :class:`.Engine`, :class:`.Connection`, or similar object to emit SQL. :param checkfirst: if ``True``, a query against the PG catalog will be first performed to see if the type actually exists before dropping. """ if not bind.dialect.supports_native_enum: return if not checkfirst or \ bind.dialect.has_type(bind, self.name, schema=self.schema): bind.execute(DropEnumType(self)) def _check_for_name_in_memos(self, checkfirst, kw): """Look in the 'ddl runner' for 'memos', then note our name in that collection. This to ensure a particular named enum is operated upon only once within any kind of create/drop sequence without relying upon "checkfirst". """ if not self.create_type: return True if '_ddl_runner' in kw: ddl_runner = kw['_ddl_runner'] if '_pg_enums' in ddl_runner.memo: pg_enums = ddl_runner.memo['_pg_enums'] else: pg_enums = ddl_runner.memo['_pg_enums'] = set() present = self.name in pg_enums pg_enums.add(self.name) return present else: return False def _on_table_create(self, target, bind, checkfirst=False, **kw): if checkfirst or ( not self.metadata and not kw.get('_is_metadata_operation', False)) and \ not self._check_for_name_in_memos(checkfirst, kw): self.create(bind=bind, checkfirst=checkfirst) def _on_table_drop(self, target, bind, checkfirst=False, **kw): if not self.metadata and \ not kw.get('_is_metadata_operation', False) and \ not self._check_for_name_in_memos(checkfirst, kw): self.drop(bind=bind, checkfirst=checkfirst) def _on_metadata_create(self, target, bind, checkfirst=False, **kw): if not self._check_for_name_in_memos(checkfirst, kw): self.create(bind=bind, checkfirst=checkfirst) def _on_metadata_drop(self, target, bind, checkfirst=False, **kw): if not self._check_for_name_in_memos(checkfirst, kw): self.drop(bind=bind, checkfirst=checkfirst) colspecs = { sqltypes.Interval: INTERVAL, sqltypes.Enum: ENUM, } ischema_names = { 'integer': INTEGER, 'bigint': BIGINT, 'smallint': SMALLINT, 'character varying': VARCHAR, 'character': CHAR, '"char"': sqltypes.String, 'name': sqltypes.String, 'text': TEXT, 'numeric': NUMERIC, 'float': FLOAT, 'real': REAL, 'inet': INET, 'cidr': CIDR, 'uuid': UUID, 'bit': BIT, 'bit varying': BIT, 'macaddr': MACADDR, 'oid': OID, 'double precision': DOUBLE_PRECISION, 'timestamp': TIMESTAMP, 'timestamp with time zone': TIMESTAMP, 'timestamp without time zone': TIMESTAMP, 'time with time zone': TIME, 'time without time zone': TIME, 'date': DATE, 'time': TIME, 'bytea': BYTEA, 'boolean': BOOLEAN, 'interval': INTERVAL, 'interval year to month': INTERVAL, 'interval day to second': INTERVAL, 'tsvector': TSVECTOR } class PGCompiler(compiler.SQLCompiler): def visit_array(self, element, **kw): return "ARRAY[%s]" % self.visit_clauselist(element, **kw) def visit_slice(self, element, **kw): return "%s:%s" % ( self.process(element.start, **kw), self.process(element.stop, **kw), ) def visit_json_getitem_op_binary(self, binary, operator, **kw): kw['eager_grouping'] = True return self._generate_generic_binary( binary, " -> ", **kw ) def visit_json_path_getitem_op_binary(self, binary, operator, **kw): kw['eager_grouping'] = True return self._generate_generic_binary( binary, " #> ", **kw ) def visit_getitem_binary(self, binary, operator, **kw): return "%s[%s]" % ( self.process(binary.left, **kw), self.process(binary.right, **kw) ) def visit_aggregate_order_by(self, element, **kw): return "%s ORDER BY %s" % ( self.process(element.target, **kw), self.process(element.order_by, **kw) ) def visit_match_op_binary(self, binary, operator, **kw): if "postgresql_regconfig" in binary.modifiers: regconfig = self.render_literal_value( binary.modifiers['postgresql_regconfig'], sqltypes.STRINGTYPE) if regconfig: return "%s @@ to_tsquery(%s, %s)" % ( self.process(binary.left, **kw), regconfig, self.process(binary.right, **kw) ) return "%s @@ to_tsquery(%s)" % ( self.process(binary.left, **kw), self.process(binary.right, **kw) ) def visit_ilike_op_binary(self, binary, operator, **kw): escape = binary.modifiers.get("escape", None) return '%s ILIKE %s' % \ (self.process(binary.left, **kw), self.process(binary.right, **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 '%s NOT ILIKE %s' % \ (self.process(binary.left, **kw), self.process(binary.right, **kw)) \ + ( ' ESCAPE ' + self.render_literal_value(escape, sqltypes.STRINGTYPE) if escape else '' ) def render_literal_value(self, value, type_): value = super(PGCompiler, self).render_literal_value(value, type_) if self.dialect._backslash_escapes: value = value.replace('\\', '\\\\') return value def visit_sequence(self, seq): return "nextval('%s')" % self.preparer.format_sequence(seq) 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 ALL" text += " OFFSET " + self.process(select._offset_clause, **kw) return text def format_from_hint_text(self, sqltext, table, hint, iscrud): if hint.upper() != 'ONLY': raise exc.CompileError("Unrecognized hint: %r" % hint) return "ONLY " + sqltext def get_select_precolumns(self, select, **kw): if select._distinct is not False: if select._distinct is True: return "DISTINCT " elif isinstance(select._distinct, (list, tuple)): return "DISTINCT ON (" + ', '.join( [self.process(col) for col in select._distinct] ) + ") " else: return "DISTINCT ON (" + \ self.process(select._distinct, **kw) + ") " else: return "" def for_update_clause(self, select, **kw): if select._for_update_arg.read: if select._for_update_arg.key_share: tmp = " FOR KEY SHARE" else: tmp = " FOR SHARE" elif select._for_update_arg.key_share: tmp = " FOR NO KEY UPDATE" else: tmp = " FOR UPDATE" if select._for_update_arg.of: tables = util.OrderedSet( c.table if isinstance(c, expression.ColumnClause) else c for c in select._for_update_arg.of) tmp += " OF " + ", ".join( self.process(table, ashint=True, use_schema=False, **kw) for table in tables ) if select._for_update_arg.nowait: tmp += " NOWAIT" if select._for_update_arg.skip_locked: tmp += " SKIP LOCKED" return tmp def returning_clause(self, stmt, returning_cols): columns = [ self._label_select_column(None, c, True, False, {}) for c in expression._select_iterables(returning_cols) ] return 'RETURNING ' + ', '.join(columns) def visit_substring_func(self, func, **kw): s = self.process(func.clauses.clauses[0], **kw) start = self.process(func.clauses.clauses[1], **kw) if len(func.clauses.clauses) > 2: length = self.process(func.clauses.clauses[2], **kw) return "SUBSTRING(%s FROM %s FOR %s)" % (s, start, length) else: return "SUBSTRING(%s FROM %s)" % (s, start) def _on_conflict_target(self, clause, **kw): if clause.constraint_target is not None: target_text = 'ON CONSTRAINT %s' % clause.constraint_target elif clause.inferred_target_elements is not None: target_text = '(%s)' % ', '.join( (self.preparer.quote(c) if isinstance(c, util.string_types) else self.process(c, include_table=False, use_schema=False)) for c in clause.inferred_target_elements ) if clause.inferred_target_whereclause is not None: target_text += ' WHERE %s' % \ self.process( clause.inferred_target_whereclause, include_table=False, use_schema=False ) else: target_text = '' return target_text def visit_on_conflict_do_nothing(self, on_conflict, **kw): target_text = self._on_conflict_target(on_conflict, **kw) if target_text: return "ON CONFLICT %s DO NOTHING" % target_text else: return "ON CONFLICT DO NOTHING" def visit_on_conflict_do_update(self, on_conflict, **kw): clause = on_conflict target_text = self._on_conflict_target(on_conflict, **kw) action_set_ops = [] set_parameters = dict(clause.update_values_to_set) # create a list of column assignment clauses as tuples cols = self.statement.table.c for c in cols: col_key = c.key if col_key in set_parameters: value = set_parameters.pop(col_key) if elements._is_literal(value): value = elements.BindParameter( None, value, type_=c.type ) else: if isinstance(value, elements.BindParameter) and \ value.type._isnull: value = value._clone() value.type = c.type value_text = self.process(value.self_group(), use_schema=False) key_text = ( self.preparer.quote(col_key) ) action_set_ops.append('%s = %s' % (key_text, value_text)) # check for names that don't match columns if set_parameters: util.warn( "Additional column names not matching " "any column keys in table '%s': %s" % ( self.statement.table.name, (", ".join("'%s'" % c for c in set_parameters)) ) ) for k, v in set_parameters.items(): key_text = ( self.preparer.quote(k) if isinstance(k, util.string_types) else self.process(k, use_schema=False) ) value_text = self.process( elements._literal_as_binds(v), use_schema=False ) action_set_ops.append('%s = %s' % (key_text, value_text)) action_text = ', '.join(action_set_ops) if clause.update_whereclause is not None: action_text += ' WHERE %s' % \ self.process( clause.update_whereclause, include_table=True, use_schema=False ) return 'ON CONFLICT %s DO UPDATE SET %s' % (target_text, action_text) class PGDDLCompiler(compiler.DDLCompiler): def get_column_specification(self, column, **kwargs): colspec = self.preparer.format_column(column) impl_type = column.type.dialect_impl(self.dialect) if isinstance(impl_type, sqltypes.TypeDecorator): impl_type = impl_type.impl if column.primary_key and \ column is column.table._autoincrement_column and \ ( self.dialect.supports_smallserial or not isinstance(impl_type, sqltypes.SmallInteger) ) and ( column.default is None or ( isinstance(column.default, schema.Sequence) and column.default.optional )): if isinstance(impl_type, sqltypes.BigInteger): colspec += " BIGSERIAL" elif isinstance(impl_type, sqltypes.SmallInteger): colspec += " SMALLSERIAL" else: colspec += " SERIAL" else: colspec += " " + 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 not column.nullable: colspec += " NOT NULL" return colspec def visit_create_enum_type(self, create): type_ = create.element return "CREATE TYPE %s AS ENUM (%s)" % ( self.preparer.format_type(type_), ", ".join( self.sql_compiler.process(sql.literal(e), literal_binds=True) for e in type_.enums) ) def visit_drop_enum_type(self, drop): type_ = drop.element return "DROP TYPE %s" % ( self.preparer.format_type(type_) ) def visit_create_index(self, create): preparer = self.preparer index = create.element self._verify_index_table(index) text = "CREATE " if index.unique: text += "UNIQUE " text += "INDEX " if self.dialect._supports_create_index_concurrently: concurrently = index.dialect_options['postgresql']['concurrently'] if concurrently: text += "CONCURRENTLY " text += "%s ON %s " % ( self._prepared_index_name(index, include_schema=False), preparer.format_table(index.table) ) using = index.dialect_options['postgresql']['using'] if using: text += "USING %s " % preparer.quote(using) ops = index.dialect_options["postgresql"]["ops"] text += "(%s)" \ % ( ', '.join([ self.sql_compiler.process( expr.self_group() if not isinstance(expr, expression.ColumnClause) else expr, include_table=False, literal_binds=True) + ( (' ' + ops[expr.key]) if hasattr(expr, 'key') and expr.key in ops else '' ) for expr in index.expressions ]) ) withclause = index.dialect_options['postgresql']['with'] if withclause: text += " WITH (%s)" % (', '.join( ['%s = %s' % storage_parameter for storage_parameter in withclause.items()])) tablespace_name = index.dialect_options['postgresql']['tablespace'] if tablespace_name: text += " TABLESPACE %s" % preparer.quote(tablespace_name) whereclause = index.dialect_options["postgresql"]["where"] if whereclause is not None: where_compiled = self.sql_compiler.process( whereclause, include_table=False, literal_binds=True) text += " WHERE " + where_compiled return text def visit_drop_index(self, drop): index = drop.element text = "\nDROP INDEX " if self.dialect._supports_drop_index_concurrently: concurrently = index.dialect_options['postgresql']['concurrently'] if concurrently: text += "CONCURRENTLY " text += self._prepared_index_name(index, include_schema=True) return text def visit_exclude_constraint(self, constraint, **kw): text = "" if constraint.name is not None: text += "CONSTRAINT %s " % \ self.preparer.format_constraint(constraint) elements = [] for expr, name, op in constraint._render_exprs: kw['include_table'] = False elements.append( "%s WITH %s" % (self.sql_compiler.process(expr, **kw), op) ) text += "EXCLUDE USING %s (%s)" % (constraint.using, ', '.join(elements)) if constraint.where is not None: text += ' WHERE (%s)' % self.sql_compiler.process( constraint.where, literal_binds=True) text += self.define_constraint_deferrability(constraint) return text def post_create_table(self, table): table_opts = [] pg_opts = table.dialect_options['postgresql'] inherits = pg_opts.get('inherits') if inherits is not None: if not isinstance(inherits, (list, tuple)): inherits = (inherits, ) table_opts.append( '\n INHERITS ( ' + ', '.join(self.preparer.quote(name) for name in inherits) + ' )') if pg_opts['with_oids'] is True: table_opts.append('\n WITH OIDS') elif pg_opts['with_oids'] is False: table_opts.append('\n WITHOUT OIDS') if pg_opts['on_commit']: on_commit_options = pg_opts['on_commit'].replace("_", " ").upper() table_opts.append('\n ON COMMIT %s' % on_commit_options) if pg_opts['tablespace']: tablespace_name = pg_opts['tablespace'] table_opts.append( '\n TABLESPACE %s' % self.preparer.quote(tablespace_name) ) return ''.join(table_opts) class PGTypeCompiler(compiler.GenericTypeCompiler): def visit_TSVECTOR(self, type, **kw): return "TSVECTOR" def visit_INET(self, type_, **kw): return "INET" def visit_CIDR(self, type_, **kw): return "CIDR" def visit_MACADDR(self, type_, **kw): return "MACADDR" def visit_OID(self, type_, **kw): return "OID" def visit_FLOAT(self, type_, **kw): if not type_.precision: return "FLOAT" else: return "FLOAT(%(precision)s)" % {'precision': type_.precision} def visit_DOUBLE_PRECISION(self, type_, **kw): return "DOUBLE PRECISION" def visit_BIGINT(self, type_, **kw): return "BIGINT" def visit_HSTORE(self, type_, **kw): return "HSTORE" def visit_JSON(self, type_, **kw): return "JSON" def visit_JSONB(self, type_, **kw): return "JSONB" def visit_INT4RANGE(self, type_, **kw): return "INT4RANGE" def visit_INT8RANGE(self, type_, **kw): return "INT8RANGE" def visit_NUMRANGE(self, type_, **kw): return "NUMRANGE" def visit_DATERANGE(self, type_, **kw): return "DATERANGE" def visit_TSRANGE(self, type_, **kw): return "TSRANGE" def visit_TSTZRANGE(self, type_, **kw): return "TSTZRANGE" def visit_datetime(self, type_, **kw): return self.visit_TIMESTAMP(type_, **kw) def visit_enum(self, type_, **kw): if not type_.native_enum or not self.dialect.supports_native_enum: return super(PGTypeCompiler, self).visit_enum(type_, **kw) else: return self.visit_ENUM(type_, **kw) def visit_ENUM(self, type_, **kw): return self.dialect.identifier_preparer.format_type(type_) def visit_TIMESTAMP(self, type_, **kw): return "TIMESTAMP%s %s" % ( "(%d)" % type_.precision if getattr(type_, 'precision', None) is not None else "", (type_.timezone and "WITH" or "WITHOUT") + " TIME ZONE" ) def visit_TIME(self, type_, **kw): return "TIME%s %s" % ( "(%d)" % type_.precision if getattr(type_, 'precision', None) is not None else "", (type_.timezone and "WITH" or "WITHOUT") + " TIME ZONE" ) def visit_INTERVAL(self, type_, **kw): if type_.precision is not None: return "INTERVAL(%d)" % type_.precision else: return "INTERVAL" def visit_BIT(self, type_, **kw): if type_.varying: compiled = "BIT VARYING" if type_.length is not None: compiled += "(%d)" % type_.length else: compiled = "BIT(%d)" % type_.length return compiled def visit_UUID(self, type_, **kw): return "UUID" def visit_large_binary(self, type_, **kw): return self.visit_BYTEA(type_, **kw) def visit_BYTEA(self, type_, **kw): return "BYTEA" def visit_ARRAY(self, type_, **kw): return self.process(type_.item_type) + ('[]' * (type_.dimensions if type_.dimensions is not None else 1)) class PGIdentifierPreparer(compiler.IdentifierPreparer): reserved_words = RESERVED_WORDS def _unquote_identifier(self, value): if value[0] == self.initial_quote: value = value[1:-1].\ replace(self.escape_to_quote, self.escape_quote) return value def format_type(self, type_, use_schema=True): if not type_.name: raise exc.CompileError("PostgreSQL ENUM type requires a name.") name = self.quote(type_.name) effective_schema = self.schema_for_object(type_) if not self.omit_schema and use_schema and \ effective_schema is not None: name = self.quote_schema(effective_schema) + "." + name return name class PGInspector(reflection.Inspector): def __init__(self, conn): reflection.Inspector.__init__(self, conn) def get_table_oid(self, table_name, schema=None): """Return the OID for the given table name.""" return self.dialect.get_table_oid(self.bind, table_name, schema, info_cache=self.info_cache) def get_enums(self, schema=None): """Return a list of ENUM objects. Each member is a dictionary containing these fields: * name - name of the enum * schema - the schema name for the enum. * visible - boolean, whether or not this enum is visible in the default search path. * labels - a list of string labels that apply to the enum. :param schema: schema name. If None, the default schema (typically 'public') is used. May also be set to '*' to indicate load enums for all schemas. .. versionadded:: 1.0.0 """ schema = schema or self.default_schema_name return self.dialect._load_enums(self.bind, schema) def get_foreign_table_names(self, schema=None): """Return a list of FOREIGN TABLE names. Behavior is similar to that of :meth:`.Inspector.get_table_names`, except that the list is limited to those tables tha report a ``relkind`` value of ``f``. .. versionadded:: 1.0.0 """ schema = schema or self.default_schema_name return self.dialect._get_foreign_table_names(self.bind, schema) def get_view_names(self, schema=None, include=('plain', 'materialized')): """Return all view names in `schema`. :param schema: Optional, retrieve names from a non-default schema. For special quoting, use :class:`.quoted_name`. :param include: specify which types of views to return. Passed as a string value (for a single type) or a tuple (for any number of types). Defaults to ``('plain', 'materialized')``. .. versionadded:: 1.1 """ return self.dialect.get_view_names(self.bind, schema, info_cache=self.info_cache, include=include) class CreateEnumType(schema._CreateDropBase): __visit_name__ = "create_enum_type" class DropEnumType(schema._CreateDropBase): __visit_name__ = "drop_enum_type" class PGExecutionContext(default.DefaultExecutionContext): def fire_sequence(self, seq, type_): return self._execute_scalar(( "select nextval('%s')" % self.dialect.identifier_preparer.format_sequence(seq)), type_) def get_insert_default(self, column): if column.primary_key and \ column is column.table._autoincrement_column: if column.server_default and column.server_default.has_argument: # pre-execute passive defaults on primary key columns return self._execute_scalar("select %s" % column.server_default.arg, column.type) elif (column.default is None or (column.default.is_sequence and column.default.optional)): # execute the sequence associated with a SERIAL primary # key column. for non-primary-key SERIAL, the ID just # generates server side. try: seq_name = column._postgresql_seq_name except AttributeError: tab = column.table.name col = column.name tab = tab[0:29 + max(0, (29 - len(col)))] col = col[0:29 + max(0, (29 - len(tab)))] name = "%s_%s_seq" % (tab, col) column._postgresql_seq_name = seq_name = name if column.table is not None: effective_schema = self.connection.schema_for_object( column.table) else: effective_schema = None if effective_schema is not None: exc = "select nextval('\"%s\".\"%s\"')" % \ (effective_schema, seq_name) else: exc = "select nextval('\"%s\"')" % \ (seq_name, ) return self._execute_scalar(exc, column.type) return super(PGExecutionContext, self).get_insert_default(column) def should_autocommit_text(self, statement): return AUTOCOMMIT_REGEXP.match(statement) class PGDialect(default.DefaultDialect): name = 'postgresql' supports_alter = True max_identifier_length = 63 supports_sane_rowcount = True supports_native_enum = True supports_native_boolean = True supports_smallserial = True supports_sequences = True sequences_optional = True preexecute_autoincrement_sequences = True postfetch_lastrowid = False supports_default_values = True supports_empty_insert = False supports_multivalues_insert = True default_paramstyle = 'pyformat' ischema_names = ischema_names colspecs = colspecs statement_compiler = PGCompiler ddl_compiler = PGDDLCompiler type_compiler = PGTypeCompiler preparer = PGIdentifierPreparer execution_ctx_cls = PGExecutionContext inspector = PGInspector isolation_level = None construct_arguments = [ (schema.Index, { "using": False, "where": None, "ops": {}, "concurrently": False, "with": {}, "tablespace": None }), (schema.Table, { "ignore_search_path": False, "tablespace": None, "with_oids": None, "on_commit": None, "inherits": None }), ] reflection_options = ('postgresql_ignore_search_path', ) _backslash_escapes = True _supports_create_index_concurrently = True _supports_drop_index_concurrently = True def __init__(self, isolation_level=None, json_serializer=None, json_deserializer=None, **kwargs): default.DefaultDialect.__init__(self, **kwargs) self.isolation_level = isolation_level self._json_deserializer = json_deserializer self._json_serializer = json_serializer def initialize(self, connection): super(PGDialect, self).initialize(connection) self.implicit_returning = self.server_version_info > (8, 2) and \ self.__dict__.get('implicit_returning', True) self.supports_native_enum = self.server_version_info >= (8, 3) if not self.supports_native_enum: self.colspecs = self.colspecs.copy() # pop base Enum type self.colspecs.pop(sqltypes.Enum, None) # psycopg2, others may have placed ENUM here as well self.colspecs.pop(ENUM, None) # http://www.postgresql.org/docs/9.3/static/release-9-2.html#AEN116689 self.supports_smallserial = self.server_version_info >= (9, 2) self._backslash_escapes = self.server_version_info < (8, 2) or \ connection.scalar( "show standard_conforming_strings" ) == 'off' self._supports_create_index_concurrently = \ self.server_version_info >= (8, 2) self._supports_drop_index_concurrently = \ self.server_version_info >= (9, 2) def on_connect(self): if self.isolation_level is not None: def connect(conn): self.set_isolation_level(conn, self.isolation_level) return connect else: return None _isolation_lookup = set(['SERIALIZABLE', 'READ UNCOMMITTED', 'READ COMMITTED', 'REPEATABLE READ']) def set_isolation_level(self, connection, level): level = level.replace('_', ' ') if level not in self._isolation_lookup: raise exc.ArgumentError( "Invalid value '%s' for isolation_level. " "Valid isolation levels for %s are %s" % (level, self.name, ", ".join(self._isolation_lookup)) ) cursor = connection.cursor() cursor.execute( "SET SESSION CHARACTERISTICS AS TRANSACTION " "ISOLATION LEVEL %s" % level) cursor.execute("COMMIT") cursor.close() def get_isolation_level(self, connection): cursor = connection.cursor() cursor.execute('show transaction isolation level') val = cursor.fetchone()[0] cursor.close() return val.upper() def do_begin_twophase(self, connection, xid): self.do_begin(connection.connection) def do_prepare_twophase(self, connection, xid): connection.execute("PREPARE TRANSACTION '%s'" % xid) def do_rollback_twophase(self, connection, xid, is_prepared=True, recover=False): if is_prepared: if recover: # FIXME: ugly hack to get out of transaction # context when committing recoverable transactions # Must find out a way how to make the dbapi not # open a transaction. connection.execute("ROLLBACK") connection.execute("ROLLBACK PREPARED '%s'" % xid) connection.execute("BEGIN") self.do_rollback(connection.connection) else: self.do_rollback(connection.connection) def do_commit_twophase(self, connection, xid, is_prepared=True, recover=False): if is_prepared: if recover: connection.execute("ROLLBACK") connection.execute("COMMIT PREPARED '%s'" % xid) connection.execute("BEGIN") self.do_rollback(connection.connection) else: self.do_commit(connection.connection) def do_recover_twophase(self, connection): resultset = connection.execute( sql.text("SELECT gid FROM pg_prepared_xacts")) return [row[0] for row in resultset] def _get_default_schema_name(self, connection): return connection.scalar("select current_schema()") def has_schema(self, connection, schema): query = ("select nspname from pg_namespace " "where lower(nspname)=:schema") cursor = connection.execute( sql.text( query, bindparams=[ sql.bindparam( 'schema', util.text_type(schema.lower()), type_=sqltypes.Unicode)] ) ) return bool(cursor.first()) def has_table(self, connection, table_name, schema=None): # seems like case gets folded in pg_class... if schema is None: cursor = connection.execute( sql.text( "select relname from pg_class c join pg_namespace n on " "n.oid=c.relnamespace where " "pg_catalog.pg_table_is_visible(c.oid) " "and relname=:name", bindparams=[ sql.bindparam('name', util.text_type(table_name), type_=sqltypes.Unicode)] ) ) else: cursor = connection.execute( sql.text( "select relname from pg_class c join pg_namespace n on " "n.oid=c.relnamespace where n.nspname=:schema and " "relname=:name", bindparams=[ sql.bindparam('name', util.text_type(table_name), type_=sqltypes.Unicode), sql.bindparam('schema', util.text_type(schema), type_=sqltypes.Unicode)] ) ) return bool(cursor.first()) def has_sequence(self, connection, sequence_name, schema=None): if schema is None: cursor = connection.execute( sql.text( "SELECT relname FROM pg_class c join pg_namespace n on " "n.oid=c.relnamespace where relkind='S' and " "n.nspname=current_schema() " "and relname=:name", bindparams=[ sql.bindparam('name', util.text_type(sequence_name), type_=sqltypes.Unicode) ] ) ) else: cursor = connection.execute( sql.text( "SELECT relname FROM pg_class c join pg_namespace n on " "n.oid=c.relnamespace where relkind='S' and " "n.nspname=:schema and relname=:name", bindparams=[ sql.bindparam('name', util.text_type(sequence_name), type_=sqltypes.Unicode), sql.bindparam('schema', util.text_type(schema), type_=sqltypes.Unicode) ] ) ) return bool(cursor.first()) def has_type(self, connection, type_name, schema=None): if schema is not None: query = """ SELECT EXISTS ( SELECT * FROM pg_catalog.pg_type t, pg_catalog.pg_namespace n WHERE t.typnamespace = n.oid AND t.typname = :typname AND n.nspname = :nspname ) """ query = sql.text(query) else: query = """ SELECT EXISTS ( SELECT * FROM pg_catalog.pg_type t WHERE t.typname = :typname AND pg_type_is_visible(t.oid) ) """ query = sql.text(query) query = query.bindparams( sql.bindparam('typname', util.text_type(type_name), type_=sqltypes.Unicode), ) if schema is not None: query = query.bindparams( sql.bindparam('nspname', util.text_type(schema), type_=sqltypes.Unicode), ) cursor = connection.execute(query) return bool(cursor.scalar()) def _get_server_version_info(self, connection): v = connection.execute("select version()").scalar() m = re.match( r'.*(?:PostgreSQL|EnterpriseDB) ' r'(\d+)\.?(\d+)?(?:\.(\d+))?(?:\.\d+)?(?:devel)?', v) if not m: raise AssertionError( "Could not determine version from string '%s'" % v) return tuple([int(x) for x in m.group(1, 2, 3) if x is not None]) @reflection.cache def get_table_oid(self, connection, table_name, schema=None, **kw): """Fetch the oid for schema.table_name. Several reflection methods require the table oid. The idea for using this method is that it can be fetched one time and cached for subsequent calls. """ table_oid = None if schema is not None: schema_where_clause = "n.nspname = :schema" else: schema_where_clause = "pg_catalog.pg_table_is_visible(c.oid)" query = """ SELECT c.oid FROM pg_catalog.pg_class c LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace WHERE (%s) AND c.relname = :table_name AND c.relkind in ('r', 'v', 'm', 'f') """ % schema_where_clause # Since we're binding to unicode, table_name and schema_name must be # unicode. table_name = util.text_type(table_name) if schema is not None: schema = util.text_type(schema) s = sql.text(query).bindparams(table_name=sqltypes.Unicode) s = s.columns(oid=sqltypes.Integer) if schema: s = s.bindparams(sql.bindparam('schema', type_=sqltypes.Unicode)) c = connection.execute(s, table_name=table_name, schema=schema) table_oid = c.scalar() if table_oid is None: raise exc.NoSuchTableError(table_name) return table_oid @reflection.cache def get_schema_names(self, connection, **kw): result = connection.execute( sql.text("SELECT nspname FROM pg_namespace " "WHERE nspname NOT LIKE 'pg_%' " "ORDER BY nspname" ).columns(nspname=sqltypes.Unicode)) return [name for name, in result] @reflection.cache def get_table_names(self, connection, schema=None, **kw): result = connection.execute( sql.text("SELECT c.relname FROM pg_class c " "JOIN pg_namespace n ON n.oid = c.relnamespace " "WHERE n.nspname = :schema AND c.relkind = 'r'" ).columns(relname=sqltypes.Unicode), schema=schema if schema is not None else self.default_schema_name) return [name for name, in result] @reflection.cache def _get_foreign_table_names(self, connection, schema=None, **kw): result = connection.execute( sql.text("SELECT c.relname FROM pg_class c " "JOIN pg_namespace n ON n.oid = c.relnamespace " "WHERE n.nspname = :schema AND c.relkind = 'f'" ).columns(relname=sqltypes.Unicode), schema=schema if schema is not None else self.default_schema_name) return [name for name, in result] @reflection.cache def get_view_names( self, connection, schema=None, include=('plain', 'materialized'), **kw): include_kind = {'plain': 'v', 'materialized': 'm'} try: kinds = [include_kind[i] for i in util.to_list(include)] except KeyError: raise ValueError( "include %r unknown, needs to be a sequence containing " "one or both of 'plain' and 'materialized'" % (include,)) if not kinds: raise ValueError( "empty include, needs to be a sequence containing " "one or both of 'plain' and 'materialized'") result = connection.execute( sql.text("SELECT c.relname FROM pg_class c " "JOIN pg_namespace n ON n.oid = c.relnamespace " "WHERE n.nspname = :schema AND c.relkind IN (%s)" % (", ".join("'%s'" % elem for elem in kinds)) ).columns(relname=sqltypes.Unicode), schema=schema if schema is not None else self.default_schema_name) return [name for name, in result] @reflection.cache def get_view_definition(self, connection, view_name, schema=None, **kw): view_def = connection.scalar( sql.text("SELECT pg_get_viewdef(c.oid) view_def FROM pg_class c " "JOIN pg_namespace n ON n.oid = c.relnamespace " "WHERE n.nspname = :schema AND c.relname = :view_name " "AND c.relkind IN ('v', 'm')" ).columns(view_def=sqltypes.Unicode), schema=schema if schema is not None else self.default_schema_name, view_name=view_name) return view_def @reflection.cache def get_columns(self, connection, table_name, schema=None, **kw): table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) SQL_COLS = """ SELECT a.attname, pg_catalog.format_type(a.atttypid, a.atttypmod), (SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid) FROM pg_catalog.pg_attrdef d WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) AS DEFAULT, a.attnotnull, a.attnum, a.attrelid as table_oid FROM pg_catalog.pg_attribute a WHERE a.attrelid = :table_oid AND a.attnum > 0 AND NOT a.attisdropped ORDER BY a.attnum """ s = sql.text(SQL_COLS, bindparams=[ sql.bindparam('table_oid', type_=sqltypes.Integer)], typemap={ 'attname': sqltypes.Unicode, 'default': sqltypes.Unicode} ) c = connection.execute(s, table_oid=table_oid) rows = c.fetchall() domains = self._load_domains(connection) enums = dict( ( "%s.%s" % (rec['schema'], rec['name']) if not rec['visible'] else rec['name'], rec) for rec in self._load_enums(connection, schema='*') ) # format columns columns = [] for name, format_type, default, notnull, attnum, table_oid in rows: column_info = self._get_column_info( name, format_type, default, notnull, domains, enums, schema) columns.append(column_info) return columns def _get_column_info(self, name, format_type, default, notnull, domains, enums, schema): # strip (*) from character varying(5), timestamp(5) # with time zone, geometry(POLYGON), etc. attype = re.sub(r'\(.*\)', '', format_type) # strip '[]' from integer[], etc. attype = attype.replace('[]', '') nullable = not notnull is_array = format_type.endswith('[]') charlen = re.search(r'\(([\d,]+)\)', format_type) if charlen: charlen = charlen.group(1) args = re.search(r'\((.*)\)', format_type) if args and args.group(1): args = tuple(re.split(r'\s*,\s*', args.group(1))) else: args = () kwargs = {} if attype == 'numeric': if charlen: prec, scale = charlen.split(',') args = (int(prec), int(scale)) else: args = () elif attype == 'double precision': args = (53, ) elif attype == 'integer': args = () elif attype in ('timestamp with time zone', 'time with time zone'): kwargs['timezone'] = True if charlen: kwargs['precision'] = int(charlen) args = () elif attype in ('timestamp without time zone', 'time without time zone', 'time'): kwargs['timezone'] = False if charlen: kwargs['precision'] = int(charlen) args = () elif attype == 'bit varying': kwargs['varying'] = True if charlen: args = (int(charlen),) else: args = () elif attype in ('interval', 'interval year to month', 'interval day to second'): if charlen: kwargs['precision'] = int(charlen) args = () elif charlen: args = (int(charlen),) while True: if attype in self.ischema_names: coltype = self.ischema_names[attype] break elif attype in enums: enum = enums[attype] coltype = ENUM kwargs['name'] = enum['name'] if not enum['visible']: kwargs['schema'] = enum['schema'] args = tuple(enum['labels']) break elif attype in domains: domain = domains[attype] attype = domain['attype'] # A table can't override whether the domain is nullable. nullable = domain['nullable'] if domain['default'] and not default: # It can, however, override the default # value, but can't set it to null. default = domain['default'] continue else: coltype = None break if coltype: coltype = coltype(*args, **kwargs) if is_array: coltype = self.ischema_names['_array'](coltype) else: util.warn("Did not recognize type '%s' of column '%s'" % (attype, name)) coltype = sqltypes.NULLTYPE # adjust the default value autoincrement = False if default is not None: match = re.search(r"""(nextval\(')([^']+)('.*$)""", default) if match is not None: if issubclass(coltype._type_affinity, sqltypes.Integer): autoincrement = True # the default is related to a Sequence sch = schema if '.' not in match.group(2) and sch is not None: # unconditionally quote the schema name. this could # later be enhanced to obey quoting rules / # "quote schema" default = match.group(1) + \ ('"%s"' % sch) + '.' + \ match.group(2) + match.group(3) column_info = dict(name=name, type=coltype, nullable=nullable, default=default, autoincrement=autoincrement) return column_info @reflection.cache def get_pk_constraint(self, connection, table_name, schema=None, **kw): table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) if self.server_version_info < (8, 4): PK_SQL = """ SELECT a.attname FROM pg_class t join pg_index ix on t.oid = ix.indrelid join pg_attribute a on t.oid=a.attrelid AND %s WHERE t.oid = :table_oid and ix.indisprimary = 't' ORDER BY a.attnum """ % self._pg_index_any("a.attnum", "ix.indkey") else: # unnest() and generate_subscripts() both introduced in # version 8.4 PK_SQL = """ SELECT a.attname FROM pg_attribute a JOIN ( SELECT unnest(ix.indkey) attnum, generate_subscripts(ix.indkey, 1) ord FROM pg_index ix WHERE ix.indrelid = :table_oid AND ix.indisprimary ) k ON a.attnum=k.attnum WHERE a.attrelid = :table_oid ORDER BY k.ord """ t = sql.text(PK_SQL, typemap={'attname': sqltypes.Unicode}) c = connection.execute(t, table_oid=table_oid) cols = [r[0] for r in c.fetchall()] PK_CONS_SQL = """ SELECT conname FROM pg_catalog.pg_constraint r WHERE r.conrelid = :table_oid AND r.contype = 'p' ORDER BY 1 """ t = sql.text(PK_CONS_SQL, typemap={'conname': sqltypes.Unicode}) c = connection.execute(t, table_oid=table_oid) name = c.scalar() return {'constrained_columns': cols, 'name': name} @reflection.cache def get_foreign_keys(self, connection, table_name, schema=None, postgresql_ignore_search_path=False, **kw): preparer = self.identifier_preparer table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) FK_SQL = """ SELECT r.conname, pg_catalog.pg_get_constraintdef(r.oid, true) as condef, n.nspname as conschema FROM pg_catalog.pg_constraint r, pg_namespace n, pg_class c WHERE r.conrelid = :table AND r.contype = 'f' AND c.oid = confrelid AND n.oid = c.relnamespace ORDER BY 1 """ # http://www.postgresql.org/docs/9.0/static/sql-createtable.html FK_REGEX = re.compile( r'FOREIGN KEY \((.*?)\) REFERENCES (?:(.*?)\.)?(.*?)\((.*?)\)' r'[\s]?(MATCH (FULL|PARTIAL|SIMPLE)+)?' r'[\s]?(ON UPDATE ' r'(CASCADE|RESTRICT|NO ACTION|SET NULL|SET DEFAULT)+)?' r'[\s]?(ON DELETE ' r'(CASCADE|RESTRICT|NO ACTION|SET NULL|SET DEFAULT)+)?' r'[\s]?(DEFERRABLE|NOT DEFERRABLE)?' r'[\s]?(INITIALLY (DEFERRED|IMMEDIATE)+)?' ) t = sql.text(FK_SQL, typemap={ 'conname': sqltypes.Unicode, 'condef': sqltypes.Unicode}) c = connection.execute(t, table=table_oid) fkeys = [] for conname, condef, conschema in c.fetchall(): m = re.search(FK_REGEX, condef).groups() constrained_columns, referred_schema, \ referred_table, referred_columns, \ _, match, _, onupdate, _, ondelete, \ deferrable, _, initially = m if deferrable is not None: deferrable = True if deferrable == 'DEFERRABLE' else False constrained_columns = [preparer._unquote_identifier(x) for x in re.split( r'\s*,\s*', constrained_columns)] if postgresql_ignore_search_path: # when ignoring search path, we use the actual schema # provided it isn't the "default" schema if conschema != self.default_schema_name: referred_schema = conschema else: referred_schema = schema elif referred_schema: # referred_schema is the schema that we regexp'ed from # pg_get_constraintdef(). If the schema is in the search # path, pg_get_constraintdef() will give us None. referred_schema = \ preparer._unquote_identifier(referred_schema) elif schema is not None and schema == conschema: # If the actual schema matches the schema of the table # we're reflecting, then we will use that. referred_schema = schema referred_table = preparer._unquote_identifier(referred_table) referred_columns = [preparer._unquote_identifier(x) for x in re.split(r'\s*,\s', referred_columns)] fkey_d = { 'name': conname, 'constrained_columns': constrained_columns, 'referred_schema': referred_schema, 'referred_table': referred_table, 'referred_columns': referred_columns, 'options': { 'onupdate': onupdate, 'ondelete': ondelete, 'deferrable': deferrable, 'initially': initially, 'match': match } } fkeys.append(fkey_d) return fkeys def _pg_index_any(self, col, compare_to): if self.server_version_info < (8, 1): # http://www.postgresql.org/message-id/10279.1124395722@sss.pgh.pa.us # "In CVS tip you could replace this with "attnum = ANY (indkey)". # Unfortunately, most array support doesn't work on int2vector in # pre-8.1 releases, so I think you're kinda stuck with the above # for now. # regards, tom lane" return "(%s)" % " OR ".join( "%s[%d] = %s" % (compare_to, ind, col) for ind in range(0, 10) ) else: return "%s = ANY(%s)" % (col, compare_to) @reflection.cache def get_indexes(self, connection, table_name, schema, **kw): table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) # cast indkey as varchar since it's an int2vector, # returned as a list by some drivers such as pypostgresql if self.server_version_info < (8, 5): IDX_SQL = """ SELECT i.relname as relname, ix.indisunique, ix.indexprs, ix.indpred, a.attname, a.attnum, NULL, ix.indkey%s, %s, am.amname FROM pg_class t join pg_index ix on t.oid = ix.indrelid join pg_class i on i.oid = ix.indexrelid left outer join pg_attribute a on t.oid = a.attrelid and %s left outer join pg_am am on i.relam = am.oid WHERE t.relkind IN ('r', 'v', 'f', 'm') and t.oid = :table_oid and ix.indisprimary = 'f' ORDER BY t.relname, i.relname """ % ( # version 8.3 here was based on observing the # cast does not work in PG 8.2.4, does work in 8.3.0. # nothing in PG changelogs regarding this. "::varchar" if self.server_version_info >= (8, 3) else "", "i.reloptions" if self.server_version_info >= (8, 2) else "NULL", self._pg_index_any("a.attnum", "ix.indkey") ) else: IDX_SQL = """ SELECT i.relname as relname, ix.indisunique, ix.indexprs, ix.indpred, a.attname, a.attnum, c.conrelid, ix.indkey::varchar, i.reloptions, am.amname FROM pg_class t join pg_index ix on t.oid = ix.indrelid join pg_class i on i.oid = ix.indexrelid left outer join pg_attribute a on t.oid = a.attrelid and a.attnum = ANY(ix.indkey) left outer join pg_constraint c on (ix.indrelid = c.conrelid and ix.indexrelid = c.conindid and c.contype in ('p', 'u', 'x')) left outer join pg_am am on i.relam = am.oid WHERE t.relkind IN ('r', 'v', 'f', 'm') and t.oid = :table_oid and ix.indisprimary = 'f' ORDER BY t.relname, i.relname """ t = sql.text(IDX_SQL, typemap={ 'relname': sqltypes.Unicode, 'attname': sqltypes.Unicode}) c = connection.execute(t, table_oid=table_oid) indexes = defaultdict(lambda: defaultdict(dict)) sv_idx_name = None for row in c.fetchall(): (idx_name, unique, expr, prd, col, col_num, conrelid, idx_key, options, amname) = row if expr: if idx_name != sv_idx_name: util.warn( "Skipped unsupported reflection of " "expression-based index %s" % idx_name) sv_idx_name = idx_name continue if prd and not idx_name == sv_idx_name: util.warn( "Predicate of partial index %s ignored during reflection" % idx_name) sv_idx_name = idx_name has_idx = idx_name in indexes index = indexes[idx_name] if col is not None: index['cols'][col_num] = col if not has_idx: index['key'] = [int(k.strip()) for k in idx_key.split()] index['unique'] = unique if conrelid is not None: index['duplicates_constraint'] = idx_name if options: index['options'] = dict( [option.split("=") for option in options]) # it *might* be nice to include that this is 'btree' in the # reflection info. But we don't want an Index object # to have a ``postgresql_using`` in it that is just the # default, so for the moment leaving this out. if amname and amname != 'btree': index['amname'] = amname result = [] for name, idx in indexes.items(): entry = { 'name': name, 'unique': idx['unique'], 'column_names': [idx['cols'][i] for i in idx['key']] } if 'duplicates_constraint' in idx: entry['duplicates_constraint'] = idx['duplicates_constraint'] if 'options' in idx: entry.setdefault( 'dialect_options', {})["postgresql_with"] = idx['options'] if 'amname' in idx: entry.setdefault( 'dialect_options', {})["postgresql_using"] = idx['amname'] result.append(entry) return result @reflection.cache def get_unique_constraints(self, connection, table_name, schema=None, **kw): table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) UNIQUE_SQL = """ SELECT cons.conname as name, cons.conkey as key, a.attnum as col_num, a.attname as col_name FROM pg_catalog.pg_constraint cons join pg_attribute a on cons.conrelid = a.attrelid AND a.attnum = ANY(cons.conkey) WHERE cons.conrelid = :table_oid AND cons.contype = 'u' """ t = sql.text(UNIQUE_SQL, typemap={'col_name': sqltypes.Unicode}) c = connection.execute(t, table_oid=table_oid) uniques = defaultdict(lambda: defaultdict(dict)) for row in c.fetchall(): uc = uniques[row.name] uc["key"] = row.key uc["cols"][row.col_num] = row.col_name return [ {'name': name, 'column_names': [uc["cols"][i] for i in uc["key"]]} for name, uc in uniques.items() ] @reflection.cache def get_check_constraints( self, connection, table_name, schema=None, **kw): table_oid = self.get_table_oid(connection, table_name, schema, info_cache=kw.get('info_cache')) CHECK_SQL = """ SELECT cons.conname as name, cons.consrc as src FROM pg_catalog.pg_constraint cons WHERE cons.conrelid = :table_oid AND cons.contype = 'c' """ c = connection.execute(sql.text(CHECK_SQL), table_oid=table_oid) return [ {'name': name, 'sqltext': src[1:-1]} for name, src in c.fetchall() ] def _load_enums(self, connection, schema=None): schema = schema or self.default_schema_name if not self.supports_native_enum: return {} # Load data types for enums: SQL_ENUMS = """ SELECT t.typname as "name", -- no enum defaults in 8.4 at least -- t.typdefault as "default", pg_catalog.pg_type_is_visible(t.oid) as "visible", n.nspname as "schema", e.enumlabel as "label" FROM pg_catalog.pg_type t LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace LEFT JOIN pg_catalog.pg_enum e ON t.oid = e.enumtypid WHERE t.typtype = 'e' """ if schema != '*': SQL_ENUMS += "AND n.nspname = :schema " # e.oid gives us label order within an enum SQL_ENUMS += 'ORDER BY "schema", "name", e.oid' s = sql.text(SQL_ENUMS, typemap={ 'attname': sqltypes.Unicode, 'label': sqltypes.Unicode}) if schema != '*': s = s.bindparams(schema=schema) c = connection.execute(s) enums = [] enum_by_name = {} for enum in c.fetchall(): key = (enum['schema'], enum['name']) if key in enum_by_name: enum_by_name[key]['labels'].append(enum['label']) else: enum_by_name[key] = enum_rec = { 'name': enum['name'], 'schema': enum['schema'], 'visible': enum['visible'], 'labels': [enum['label']], } enums.append(enum_rec) return enums def _load_domains(self, connection): # Load data types for domains: SQL_DOMAINS = """ SELECT t.typname as "name", pg_catalog.format_type(t.typbasetype, t.typtypmod) as "attype", not t.typnotnull as "nullable", t.typdefault as "default", pg_catalog.pg_type_is_visible(t.oid) as "visible", n.nspname as "schema" FROM pg_catalog.pg_type t LEFT JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace WHERE t.typtype = 'd' """ s = sql.text(SQL_DOMAINS, typemap={'attname': sqltypes.Unicode}) c = connection.execute(s) domains = {} for domain in c.fetchall(): # strip (30) from character varying(30) attype = re.search(r'([^\(]+)', domain['attype']).group(1) if domain['visible']: # 'visible' just means whether or not the domain is in a # schema that's on the search path -- or not overridden by # a schema with higher precedence. If it's not visible, # it will be prefixed with the schema-name when it's used. name = domain['name'] else: name = "%s.%s" % (domain['schema'], domain['name']) domains[name] = { 'attype': attype, 'nullable': domain['nullable'], 'default': domain['default'] } return domains