From: Federico Caselli Date: Sun, 10 Oct 2021 08:41:13 +0000 (+0200) Subject: The ``has_table`` method now also checks views X-Git-Tag: rel_2_0_0b1~687 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=de61582933b800272cc818d36de9e0b7f86aa4fe;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git The ``has_table`` method now also checks views The :meth:`_engine.Inspector.has_table` method will now consistently check for views of the given name as well as tables. Previously this behavior was dialect dependent, with PostgreSQL, MySQL/MariaDB and SQLite supporting it, and Oracle and SQL Server not supporting it. Third party dialects should also seek to ensure their :meth:`_engine.Inspector.has_table` method searches for views as well as tables for the given name. Fixes: #7161 Change-Id: I9e523c76741b19596c81ef577dc6f0823e44183b --- diff --git a/doc/build/changelog/unreleased_20/7161.rst b/doc/build/changelog/unreleased_20/7161.rst new file mode 100644 index 0000000000..ec584b3a97 --- /dev/null +++ b/doc/build/changelog/unreleased_20/7161.rst @@ -0,0 +1,10 @@ +.. change:: + :tags: engine, bug + :tickets: 7161 + + The :meth:`_engine.Inspector.has_table` method will now consistently check + for views of the given name as well as tables. Previously this behavior was + dialect dependent, with PostgreSQL, MySQL/MariaDB and SQLite supporting it, + and Oracle and SQL Server not supporting it. Third party dialects should + also seek to ensure their :meth:`_engine.Inspector.has_table` method + searches for views as well as tables for the given name. \ No newline at end of file diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py index 95ccd2ca89..8c8260f3bb 100644 --- a/lib/sqlalchemy/dialects/mssql/base.py +++ b/lib/sqlalchemy/dialects/mssql/base.py @@ -2888,6 +2888,8 @@ class MSDialect(default.DefaultDialect): def has_table(self, connection, tablename, dbname, owner, schema): self._ensure_has_table_connection(connection) if tablename.startswith("#"): # temporary table + # mssql does not support temporary views + # SQL Error [4103] [S0001]: "#v": Temporary views are not allowed tables = ischema.mssql_temp_table_columns s = sql.select(tables.c.table_name).where( @@ -2915,7 +2917,10 @@ class MSDialect(default.DefaultDialect): s = sql.select(tables.c.table_name).where( sql.and_( - tables.c.table_type == "BASE TABLE", + sql.or_( + tables.c.table_type == "BASE TABLE", + tables.c.table_type == "VIEW", + ), tables.c.table_name == tablename, ) ) diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py index 8b790c70c6..c0bf985e56 100644 --- a/lib/sqlalchemy/dialects/oracle/base.py +++ b/lib/sqlalchemy/dialects/oracle/base.py @@ -1611,9 +1611,14 @@ class OracleDialect(default.DefaultDialect): cursor = connection.execute( sql.text( - "SELECT table_name FROM all_tables " - "WHERE table_name = CAST(:name AS VARCHAR2(128)) " - "AND owner = CAST(:schema_name AS VARCHAR2(128))" + """SELECT table_name FROM all_tables + WHERE table_name = CAST(:name AS VARCHAR2(128)) + AND owner = CAST(:schema_name AS VARCHAR2(128)) + UNION ALL + SELECT view_name FROM all_views + WHERE view_name = CAST(:name AS VARCHAR2(128)) + AND owner = CAST(:schema_name AS VARCHAR2(128)) + """ ), dict( name=self.denormalize_name(table_name), diff --git a/lib/sqlalchemy/engine/interfaces.py b/lib/sqlalchemy/engine/interfaces.py index d1484718eb..fdaeaddcdc 100644 --- a/lib/sqlalchemy/engine/interfaces.py +++ b/lib/sqlalchemy/engine/interfaces.py @@ -463,7 +463,7 @@ class Dialect(object): def has_table(self, connection, table_name, schema=None, **kw): """For internal dialect use, check the existence of a particular table - in the database. + or view in the database. Given a :class:`_engine.Connection` object, a string table_name and optional schema name, return True if the given table exists in the @@ -481,6 +481,13 @@ class Dialect(object): Alternatively, for legacy cross-compatibility, the :meth:`_engine.Engine.has_table` method may be used. + .. versionchanged:: 2.0 + + The :meth:`_engine.Dialect.has_table` method should also check + for the presence of views. In previous versions this + behavior was dialect specific. New dialect suite tests were added + to ensure that dialects conform with this behavior consistently. + """ raise NotImplementedError() diff --git a/lib/sqlalchemy/engine/reflection.py b/lib/sqlalchemy/engine/reflection.py index 113aa8ea06..d8c2bcbd7c 100644 --- a/lib/sqlalchemy/engine/reflection.py +++ b/lib/sqlalchemy/engine/reflection.py @@ -268,8 +268,7 @@ class Inspector(object): ) def has_table(self, table_name, schema=None): - """Return True if the backend has a table of the given name. - + """Return True if the backend has a table or view of the given name. :param table_name: name of the table to check :param schema: schema name to query, if not the default schema. @@ -277,6 +276,11 @@ class Inspector(object): .. versionadded:: 1.4 - the :meth:`.Inspector.has_table` method replaces the :meth:`_engine.Engine.has_table` method. + .. versionchanged:: 2.0:: The method checks also for views. + In previous version this behaviour was dialect specific. New + dialect suite tests were added to ensure all dialect conform with + this behaviour. + """ # TODO: info_cache? with self._operation_context() as conn: diff --git a/lib/sqlalchemy/testing/suite/test_reflection.py b/lib/sqlalchemy/testing/suite/test_reflection.py index 88189c2d95..6fbd746891 100644 --- a/lib/sqlalchemy/testing/suite/test_reflection.py +++ b/lib/sqlalchemy/testing/suite/test_reflection.py @@ -77,6 +77,32 @@ class HasTableTest(fixtures.TablesTest): ) ) + @testing.requires.views + def test_has_table_view(self, connection): + query = "CREATE VIEW vv AS SELECT * FROM test_table" + connection.execute(sa.sql.text(query)) + insp = inspect(connection) + try: + is_true(insp.has_table("vv")) + finally: + connection.execute(sa.sql.text("DROP VIEW vv")) + + @testing.requires.views + @testing.requires.schemas + def test_has_table_view_schema(self, connection): + query = "CREATE VIEW %s.vv AS SELECT * FROM %s.test_table_s" % ( + config.test_schema, + config.test_schema, + ) + connection.execute(sa.sql.text(query)) + insp = inspect(connection) + try: + is_true(insp.has_table("vv", config.test_schema)) + finally: + connection.execute( + sa.sql.text("DROP VIEW %s.vv" % config.test_schema) + ) + class HasIndexTest(fixtures.TablesTest): __backend__ = True