diff options
Diffstat (limited to 'lib/sqlalchemy/sql/functions.py')
-rw-r--r-- | lib/sqlalchemy/sql/functions.py | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/lib/sqlalchemy/sql/functions.py b/lib/sqlalchemy/sql/functions.py index 7efb1e916..9280c7d60 100644 --- a/lib/sqlalchemy/sql/functions.py +++ b/lib/sqlalchemy/sql/functions.py @@ -12,7 +12,7 @@ from . import sqltypes, schema from .base import Executable, ColumnCollection from .elements import ClauseList, Cast, Extract, _literal_as_binds, \ literal_column, _type_from_args, ColumnElement, _clone,\ - Over, BindParameter + Over, BindParameter, FunctionFilter from .selectable import FromClause, Select, Alias from . import operators @@ -116,6 +116,35 @@ class FunctionElement(Executable, ColumnElement, FromClause): """ return Over(self, partition_by=partition_by, order_by=order_by) + def filter(self, *criterion): + """Produce a FILTER clause against this function. + + Used against aggregate and window functions, + for database backends that support the "FILTER" clause. + + The expression:: + + func.count(1).filter(True) + + is shorthand for:: + + from sqlalchemy import funcfilter + funcfilter(func.count(1), True) + + .. versionadded:: 1.0.0 + + .. seealso:: + + :class:`.FunctionFilter` + + :func:`.funcfilter` + + + """ + if not criterion: + return self + return FunctionFilter(self, *criterion) + @property def _from_objects(self): return self.clauses._from_objects |