diff options
Diffstat (limited to 'lib/sqlalchemy/sql/elements.py')
| -rw-r--r-- | lib/sqlalchemy/sql/elements.py | 62 |
1 files changed, 40 insertions, 22 deletions
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py index 6ce505412..c7e5aabcc 100644 --- a/lib/sqlalchemy/sql/elements.py +++ b/lib/sqlalchemy/sql/elements.py @@ -2573,10 +2573,8 @@ class Case(ColumnElement): stmt = select([users_table]).\ where( case( - [ - (users_table.c.name == 'wendy', 'W'), - (users_table.c.name == 'jack', 'J') - ], + (users_table.c.name == 'wendy', 'W'), + (users_table.c.name == 'jack', 'J'), else_='E' ) ) @@ -2597,7 +2595,10 @@ class Case(ColumnElement): ("else_", InternalTraversal.dp_clauseelement), ] - def __init__(self, whens, value=None, else_=None): + # TODO: for Py2k removal, this will be: + # def __init__(self, *whens, value=None, else_=None): + + def __init__(self, *whens, **kw): r"""Produce a ``CASE`` expression. The ``CASE`` construct in SQL is a conditional object that @@ -2612,10 +2613,8 @@ class Case(ColumnElement): stmt = select([users_table]).\ where( case( - [ - (users_table.c.name == 'wendy', 'W'), - (users_table.c.name == 'jack', 'J') - ], + (users_table.c.name == 'wendy', 'W'), + (users_table.c.name == 'jack', 'J'), else_='E' ) ) @@ -2660,16 +2659,14 @@ class Case(ColumnElement): from sqlalchemy import case, literal_column case( - [ - ( - orderline.c.qty > 100, - literal_column("'greaterthan100'") - ), - ( - orderline.c.qty > 10, - literal_column("'greaterthan10'") - ) - ], + ( + orderline.c.qty > 100, + literal_column("'greaterthan100'") + ), + ( + orderline.c.qty > 10, + literal_column("'greaterthan10'") + ), else_=literal_column("'lessthan10'") ) @@ -2683,19 +2680,23 @@ class Case(ColumnElement): ELSE 'lessthan10' END - :param whens: The criteria to be compared against, + :param \*whens: The criteria to be compared against, :paramref:`.case.whens` accepts two different forms, based on whether or not :paramref:`.case.value` is used. + .. versionchanged:: 1.4 the :func:`_sql.case` + function now accepts the series of WHEN conditions positionally; + passing the expressions within a list is deprecated. + In the first form, it accepts a list of 2-tuples; each 2-tuple consists of ``(<sql expression>, <value>)``, where the SQL expression is a boolean expression and "value" is a resulting value, e.g.:: - case([ + case( (users_table.c.name == 'wendy', 'W'), (users_table.c.name == 'jack', 'J') - ]) + ) In the second form, it accepts a Python dictionary of comparison values mapped to a resulting value; this form requires @@ -2720,11 +2721,23 @@ class Case(ColumnElement): """ + if "whens" in kw: + util.warn_deprecated_20( + 'The "whens" argument to case() is now passed as a series of ' + "positional " + "elements, rather than as a list. " + ) + whens = kw.pop("whens") + else: + whens = coercions._expression_collection_was_a_list( + "whens", "case", whens + ) try: whens = util.dictlike_iteritems(whens) except TypeError: pass + value = kw.pop("value", None) if value is not None: whenlist = [ ( @@ -2760,11 +2773,16 @@ class Case(ColumnElement): self.type = type_ self.whens = whenlist + + else_ = kw.pop("else_", None) if else_ is not None: self.else_ = coercions.expect(roles.ExpressionElementRole, else_) else: self.else_ = None + if kw: + raise TypeError("unknown arguments: %s" % (", ".join(sorted(kw)))) + @property def _from_objects(self): return list( |