pass asfrom correctly in compilers

Fixed an argument error in the default and PostgreSQL compilers that
would interfere with an UPDATE..FROM or DELETE..FROM..USING statement
that was then SELECTed from as a CTE.

The incorrect pattern was also fixed in the mysql and sybase dialects.
MySQL supports CTEs but not "returning".

Fixes: #6303
Change-Id: Ic94805611a5ec443749fb6b1fd8a1326b0d83ef7

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index c5113b054..d4c70a78e 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1783,8 +1783,9 @@ class MySQLCompiler(compiler.SQLCompiler):
             return None
 
     def update_tables_clause(self, update_stmt, from_table, extra_froms, **kw):
+        kw["asfrom"] = True
         return ", ".join(
-            t._compiler_dispatch(self, asfrom=True, **kw)
+            t._compiler_dispatch(self, **kw)
             for t in [from_table] + list(extra_froms)
         )
 
@@ -1806,8 +1807,9 @@ class MySQLCompiler(compiler.SQLCompiler):
         self, delete_stmt, from_table, extra_froms, from_hints, **kw
     ):
         """Render the DELETE .. USING clause specific to MySQL."""
+        kw["asfrom"] = True
         return "USING " + ", ".join(
-            t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw)
+            t._compiler_dispatch(self, fromhints=from_hints, **kw)
             for t in [from_table] + extra_froms
         )