diff options
Diffstat (limited to 'lib/sqlalchemy/sql/operators.py')
| -rw-r--r-- | lib/sqlalchemy/sql/operators.py | 28 |
1 files changed, 7 insertions, 21 deletions
diff --git a/lib/sqlalchemy/sql/operators.py b/lib/sqlalchemy/sql/operators.py index 3aeaaa601..22bf3d150 100644 --- a/lib/sqlalchemy/sql/operators.py +++ b/lib/sqlalchemy/sql/operators.py @@ -538,17 +538,15 @@ class ColumnOperators(Operators): stmt.where(column.in_([])) - In this calling form, the expression renders a "false" expression, - e.g.:: + In this calling form, the expression renders an "empty set" + expression. These expressions are tailored to individual backends + and are generaly trying to get an empty SELECT statement as a + subuqery. Such as on SQLite, the expression is:: - WHERE 1 != 1 + WHERE col IN (SELECT 1 FROM (SELECT 1) WHERE 1!=1) - This "false" expression has historically had different behaviors - in older SQLAlchemy versions, see - :paramref:`.create_engine.empty_in_strategy` for behavioral options. - - .. versionchanged:: 1.2 simplified the behavior of "empty in" - expressions + .. versionchanged:: 1.4 empty IN expressions now use an + execution-time generated SELECT subquery in all cases. * A bound parameter, e.g. :func:`.bindparam`, may be used if it includes the :paramref:`.bindparam.expanding` flag:: @@ -1341,16 +1339,6 @@ def comma_op(a, b): raise NotImplementedError() -@comparison_op -def empty_in_op(a, b): - raise NotImplementedError() - - -@comparison_op -def empty_notin_op(a, b): - raise NotImplementedError() - - def filter_op(a, b): raise NotImplementedError() @@ -1473,8 +1461,6 @@ _PRECEDENCE = { ne: 5, is_distinct_from: 5, isnot_distinct_from: 5, - empty_in_op: 5, - empty_notin_op: 5, gt: 5, lt: 5, ge: 5, |