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| author | Sebastian Bank <sebastian.bank@uni-leipzig.de> | 2016-04-11 23:16:32 -0400 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2016-06-06 15:53:25 -0400 |
| commit | 3351f5f93ca1968653becbed7f1ddef7afb96077 (patch) | |
| tree | 0bc2a08dd5809522e23eed7a47b9f11bf95ad4b2 /doc | |
| parent | a5f92314edd45a2e411b0f5b3c4d4bec0c7d92f8 (diff) | |
| download | sqlalchemy-3351f5f93ca1968653becbed7f1ddef7afb96077.tar.gz | |
Add IS (NOT) DISTINCT FROM operators
None / True / False render as literals.
For SQLite, "IS" is used as SQLite lacks
"IS DISTINCT FROM" but its "IS" operator acts
this way for NULL.
Doctext-author: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: I9227b81f7207b42627a0349d14d40b46aa756cce
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/248
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/build/changelog/changelog_11.rst | 11 | ||||
| -rw-r--r-- | doc/build/changelog/migration_11.rst | 24 |
2 files changed, 35 insertions, 0 deletions
diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst index 709eaab5e..789a241d0 100644 --- a/doc/build/changelog/changelog_11.rst +++ b/doc/build/changelog/changelog_11.rst @@ -134,6 +134,17 @@ :ref:`change_3653` .. change:: + :tags: feature, sql + + New :meth:`.ColumnOperators.is_distinct_from` and + :meth:`.ColumnOperators.isnot_distinct_from` operators; pull request + courtesy Sebastian Bank. + + .. seealso:: + + :ref:`change_is_distinct_from` + + .. change:: :tags: bug, orm :tickets: 3488 diff --git a/doc/build/changelog/migration_11.rst b/doc/build/changelog/migration_11.rst index b217f0420..d9f48fcb1 100644 --- a/doc/build/changelog/migration_11.rst +++ b/doc/build/changelog/migration_11.rst @@ -1137,6 +1137,30 @@ will not have much impact on the behavior of the column during an INSERT. :ticket:`3216` +.. _change_is_distinct_from: + +Support for IS DISTINCT FROM and IS NOT DISTINCT FROM +------------------------------------------------------ + +New operators :meth:`.ColumnOperators.is_distinct_from` and +:meth:`.ColumnOperators.isnot_distinct_from` allow the IS DISTINCT +FROM and IS NOT DISTINCT FROM sql operation:: + + >>> print column('x').is_distinct_from(None) + x IS DISTINCT FROM NULL + +Handling is provided for NULL, True and False:: + + >>> print column('x').isnot_distinct_from(False) + x IS NOT DISTINCT FROM false + +For SQLite, which doesn't have this operator, "IS" / "IS NOT" is rendered, +which on SQLite works for NULL unlike other backends:: + + >>> from sqlalchemy.dialects import sqlite + >>> print column('x').is_distinct_from(None).compile(dialect=sqlite.dialect()) + x IS NOT NULL + .. _change_1957: Core and ORM support for FULL OUTER JOIN |