diff options
Diffstat (limited to 'lib/sqlalchemy/engine/interfaces.py')
| -rw-r--r-- | lib/sqlalchemy/engine/interfaces.py | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/lib/sqlalchemy/engine/interfaces.py b/lib/sqlalchemy/engine/interfaces.py index 5e6cc524e..47348ba76 100644 --- a/lib/sqlalchemy/engine/interfaces.py +++ b/lib/sqlalchemy/engine/interfaces.py @@ -467,12 +467,25 @@ class Dialect(object): raise NotImplementedError() def has_table(self, connection, table_name, schema=None, **kw): - """Check the existence of a particular table in the database. + """For internal dialect use, check the existence of a particular table + 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 + database, False otherwise. + + This method serves as the underlying implementation of the + public facing :meth:`.Inspector.has_table` method, and is also used + internally to implement the "checkfirst" behavior for methods like + :meth:`_schema.Table.create` and :meth:`_schema.MetaData.create_all`. + + .. note:: This method is used internally by SQLAlchemy, and is + published so that third-party dialects may provide an + implementation. It is **not** the public API for checking for table + presence. Please use the :meth:`.Inspector.has_table` method. + Alternatively, for legacy cross-compatibility, the + :meth:`_engine.Engine.has_table` method may be used. - Given a :class:`_engine.Connection` object and a string - `table_name`, return True if the given table (possibly within - the specified `schema`) exists in the database, False - otherwise. """ raise NotImplementedError() |