- The system by which a :class:`.Column` considers itself to be an

"auto increment" column has been changed, such that autoincrement
is no longer implicitly enabled for a :class:`.Table` that has a
composite primary key.  In order to accommodate being able to enable
autoincrement for a composite PK member column while at the same time
maintaining SQLAlchemy's long standing behavior of enabling
implicit autoincrement for a single integer primary key, a third
state has been added to the :paramref:`.Column.autoincrement` parameter
``"auto"``, which is now the default. fixes #3216
- The MySQL dialect no longer generates an extra "KEY" directive when
generating CREATE TABLE DDL for a table using InnoDB with a
composite primary key with AUTO_INCREMENT on a column that isn't the
first column;  to overcome InnoDB's limitation here, the PRIMARY KEY
constraint is now generated with the AUTO_INCREMENT column placed
first in the list of columns.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 691195772..f1220ce31 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -2381,7 +2381,7 @@ class DDLCompiler(Compiled):
                 text += "CONSTRAINT %s " % formatted_name
         text += "PRIMARY KEY "
         text += "(%s)" % ', '.join(self.preparer.quote(c.name)
-                                   for c in constraint)
+                                   for c in constraint.columns_autoinc_first)
         text += self.define_constraint_deferrability(constraint)
         return text