Applied fix from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff to defer constraint checks when loading fixtures.

 - Legacy-Id: 5818

Author: levkowetz

django/core/management/commands/loaddata.py

@@ -81,6 +81,10 @@ def read(self):
         if has_bz2:
             compression_types['bz2'] = bz2.BZ2File
 
+        # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+        connection.begin_defer_constraint_checks()
+	         
+
         app_module_paths = []
         for app in get_apps():
             if hasattr(app, '__path__'):
@@ -118,6 +122,9 @@ def read(self):
                 self.stderr.write(
                     self.style.ERROR("Problem installing fixture '%s': %s is not a known serialization format.\n" %
                         (fixture_name, format)))
+                # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+                connection.end_defer_constraint_checks()
+
                 if commit:
                     transaction.rollback(using=using)
                     transaction.leave_transaction_management(using=using)
@@ -153,6 +160,9 @@ def read(self):
                             fixture.close()
                             self.stderr.write(self.style.ERROR("Multiple fixtures named '%s' in %s. Aborting.\n" %
                                 (fixture_name, humanize(fixture_dir))))
+                            # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+                            connection.end_defer_constraint_checks()
+
                             if commit:
                                 transaction.rollback(using=using)
                                 transaction.leave_transaction_management(using=using)
@@ -180,6 +190,10 @@ def read(self):
                             except Exception:
                                 import traceback
                                 fixture.close()
+
+                                # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+                                connection.end_defer_constraint_checks()
+
                                 if commit:
                                     transaction.rollback(using=using)
                                     transaction.leave_transaction_management(using=using)
@@ -199,6 +213,9 @@ def read(self):
                                 self.stderr.write(
                                     self.style.ERROR("No fixture data found for '%s'. (File format may be invalid.)\n" %
                                         (fixture_name)))
+                                # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+                                connection.end_defer_constraint_checks()
+
                                 if commit:
                                     transaction.rollback(using=using)
                                     transaction.leave_transaction_management(using=using)
@@ -219,6 +236,9 @@ def read(self):
                 for line in sequence_sql:
                     cursor.execute(line)
 
+        # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+        connection.end_defer_constraint_checks()
+
         if commit:
             transaction.commit(using=using)
             transaction.leave_transaction_management(using=using)

django/db/backends/__init__.py

@@ -65,6 +65,13 @@ def _savepoint_commit(self, sid):
             return
         self.cursor().execute(self.ops.savepoint_commit_sql(sid))
 
+    # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+    def begin_defer_constraint_checks(self):
+        return None
+   
+    def end_defer_constraint_checks(self):
+        return None
+
     def close(self):
         if self.connection is not None:
             self.connection.close()

django/db/backends/mysql/base.py

@@ -316,3 +316,10 @@ def get_server_version(self):
                 raise Exception('Unable to determine MySQL version from version string %r' % self.connection.get_server_info())
             self.server_version = tuple([int(x) for x in m.groups()])
         return self.server_version
+
+    # from https://code.djangoproject.com/attachment/ticket/3615/defer_constraint_checks.diff
+    def begin_defer_constraint_checks(self):
+        self.cursor().execute('SET foreign_key_checks=0')
+       
+    def end_defer_constraint_checks(self):
+        self.cursor().execute('SET foreign_key_checks=1')