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Diffstat (limited to 'doc/build/changelog/migration_13.rst')
| -rw-r--r-- | doc/build/changelog/migration_13.rst | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/doc/build/changelog/migration_13.rst b/doc/build/changelog/migration_13.rst index 5a8e3ce05..40363d426 100644 --- a/doc/build/changelog/migration_13.rst +++ b/doc/build/changelog/migration_13.rst @@ -413,6 +413,24 @@ backend, such as "SELECT CAST(NULL AS INTEGER) WHERE 1!=1" for Postgresql, ... SELECT 1 WHERE 1 IN (SELECT CAST(NULL AS INTEGER) WHERE 1!=1) +The feature also works for tuple-oriented IN statements, where the "empty IN" +expression will be expanded to support the elements given inside the tuple, +such as on Postgresql:: + + >>> from sqlalchemy import create_engine + >>> from sqlalchemy import select, literal_column, tuple_, bindparam + >>> e = create_engine("postgresql://scott:tiger@localhost/test", echo=True) + >>> with e.connect() as conn: + ... conn.execute( + ... select([literal_column('1')]). + ... where(tuple_(50, "somestring").in_(bindparam('q', expanding=True))), + ... q=[] + ... ) + ... + SELECT 1 WHERE (%(param_1)s, %(param_2)s) + IN (SELECT CAST(NULL AS INTEGER), CAST(NULL AS VARCHAR) WHERE 1!=1) + + :ticket:`4271` .. _change_3981: |