diff --git a/django/db/backends/ado_mssql/base.py b/django/db/backends/ado_mssql/base.py
index 25832e25df..8d813c6704 100644
--- a/django/db/backends/ado_mssql/base.py
+++ b/django/db/backends/ado_mssql/base.py
@@ -70,7 +70,8 @@ class DatabaseWrapper(object):
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection:
+            return self.connection.commit()
 
     def _rollback(self):
         if self.connection:
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index b760f47786..6040b9c5f3 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -91,7 +91,8 @@ class DatabaseWrapper(object):
         return cursor
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection:
+            self.connection.commit()
 
     def _rollback(self):
         if self.connection:
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index a9a0662c15..754fcef776 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -36,7 +36,8 @@ class DatabaseWrapper(object):
         return FormatStylePlaceholderCursor(self.connection)
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection:
+            self.connection.commit()
 
     def _rollback(self):
         if self.connection:
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 774b52a1d6..cc6686ed81 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -43,7 +43,8 @@ class DatabaseWrapper(object):
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection:
+            return self.connection.commit()
 
     def _rollback(self):
         if self.connection:
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 65f3e698ae..d62376596f 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -44,7 +44,8 @@ class DatabaseWrapper(object):
         return cursor
 
     def _commit(self):
-        return self.connection.commit()
+        if self.connection:
+            return self.connection.commit()
 
     def _rollback(self):
         if self.connection:
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index e6aff2d847..2d42700e63 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -56,7 +56,8 @@ class DatabaseWrapper(local):
             return cursor
 
     def _commit(self):
-        self.connection.commit()
+        if self.connection:
+            self.connection.commit()
 
     def _rollback(self):
         if self.connection: