diff options
Diffstat (limited to 'lib/sqlalchemy/sql')
| -rw-r--r-- | lib/sqlalchemy/sql/selectable.py | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py index 2263073c4..c93de8d73 100644 --- a/lib/sqlalchemy/sql/selectable.py +++ b/lib/sqlalchemy/sql/selectable.py @@ -1280,6 +1280,10 @@ class Alias(AliasedReturnsRows): level function as well as the :meth:`.FromClause.alias` method available on all :class:`.FromClause` subclasses. + .. seealso:: + + :meth:`.FromClause.alias` + """ __visit_name__ = "alias" @@ -1710,6 +1714,28 @@ class HasCTE(roles.HasCTERole): class Subquery(AliasedReturnsRows): + """Represent a subquery of a SELECT. + + A :class:`.Subquery` is created by invoking the + :meth:`.SelectBase.subquery` method, or for convenience the + :class:`.SelectBase.alias` method, on any :class:`.SelectBase` subclass + which includes :class:`.Select`, :class:`.CompoundSelect`, and + :class:`.TextualSelect`. As rendered in a FROM clause, it represents the + body of the SELECT statement inside of parenthesis, followed by the usual + "AS <somename>" that defines all "alias" objects. + + The :class:`.Subquery` object is very similar to the :class:`.Alias` + object and can be used in an equivalent way. The difference between + :class:`.Alias` and :class:`.Subquery` is that :class:`.Alias` always + contains a :class:`.FromClause` object whereas :class:`.Subquery` + always contains a :class:`.SelectBase` object. + + .. versionadded:: 1.4 The :class:`.Subquery` class was added which now + serves the purpose of providing an aliased version of a SELECT + statement. + + """ + __visit_name__ = "subquery" _is_subquery = True |
