- 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, 0 insertions, 31 deletions

diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index 4b3e5bcd1..2c78de2fc 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -1916,38 +1916,7 @@ class MySQLCompiler(compiler.SQLCompiler):
         return None
 
 
-# ug.  "InnoDB needs indexes on foreign keys and referenced keys [...].
-#       Starting with MySQL 4.1.2, these indexes are created automatically.
-#       In older versions, the indexes must be created explicitly or the
-#       creation of foreign key constraints fails."
-
 class MySQLDDLCompiler(compiler.DDLCompiler):
-    def create_table_constraints(self, table, **kw):
-        """Get table constraints."""
-        constraint_string = super(
-            MySQLDDLCompiler, self).create_table_constraints(table, **kw)
-
-        # why self.dialect.name and not 'mysql'?  because of drizzle
-        is_innodb = 'engine' in table.dialect_options[self.dialect.name] and \
-                    table.dialect_options[self.dialect.name][
-                        'engine'].lower() == 'innodb'
-
-        auto_inc_column = table._autoincrement_column
-
-        if is_innodb and \
-                auto_inc_column is not None and \
-                auto_inc_column is not list(table.primary_key)[0]:
-            if constraint_string:
-                constraint_string += ", \n\t"
-            constraint_string += "KEY %s (%s)" % (
-                self.preparer.quote(
-                    "idx_autoinc_%s" % auto_inc_column.name
-                ),
-                self.preparer.format_column(auto_inc_column)
-            )
-
-        return constraint_string
-
     def get_column_specification(self, column, **kw):
         """Builds column DDL."""