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| author | Federico Caselli <cfederico87@gmail.com> | 2020-04-16 23:16:32 +0200 |
|---|---|---|
| committer | Mike Bayer <mike_mp@zzzcomputing.com> | 2020-04-20 11:28:51 -0400 |
| commit | 07d6d211f23f1d9d1d69fd54e8054bccd515bc8c (patch) | |
| tree | 321a19e49f8918ec38bba96bf4c062633801bd26 /lib/sqlalchemy/sql/compiler.py | |
| parent | 2f617f56f2acdce00b88f746c403cf5ed66d4d27 (diff) | |
| download | sqlalchemy-07d6d211f23f1d9d1d69fd54e8054bccd515bc8c.tar.gz | |
Deprecate ``DISTINCT ON`` when not targeting PostgreSQL
Deprecate usage of ``DISTINCT ON`` in dialect other than PostgreSQL.
Previously this was silently ignored.
Deprecate old usage of string distinct in MySQL dialect
Fixes: #4002
Change-Id: I38fc64aef75e77748083c11d388ec831f161c9c9
Diffstat (limited to 'lib/sqlalchemy/sql/compiler.py')
| -rw-r--r-- | lib/sqlalchemy/sql/compiler.py | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py index bc16b1429..23eff773c 100644 --- a/lib/sqlalchemy/sql/compiler.py +++ b/lib/sqlalchemy/sql/compiler.py @@ -2868,7 +2868,16 @@ class SQLCompiler(Compiled): before column list. """ - return select._distinct and "DISTINCT " or "" + if select._distinct_on: + util.warn_deprecated( + "DISTINCT ON is currently supported only by the PostgreSQL " + "dialect. Use of DISTINCT ON for other backends is currently " + "silently ignored, however this usage is deprecated, and will " + "raise CompileError in a future release for all backends " + "that do not support this syntax.", + version="1.4", + ) + return "DISTINCT " if select._distinct else "" def group_by_clause(self, select, **kw): """allow dialects to customize how GROUP BY is rendered.""" |