SQL scripts should not manage transactions

Cinder SQL scripts assume too much about the environment and the way in
which they are executed by sqlalchemy-migrate. Particularly, they manage
transactions on their own even though sqlalchemy-migrate do it itself,
plus it assumes that scripts are executed in one go (even though
standard Python DB-API 2.0 does not mention multi-statement SQL commands
to be executed on DB cursors.

blueprint enable-mysql-connector

Change-Id: I10c58b3af75d3ab9153a8bbd2a539bf1577de328
Closes-Bug: 1368391

cinder/db/sqlalchemy/migrate_repo/versions/005_sqlite_downgrade.sql

@@ -1,5 +1,3 @@
-BEGIN TRANSACTION;
-
 CREATE TEMPORARY TABLE volumes_backup (
     created_at DATETIME,
     updated_at DATETIME,
@@ -121,4 +119,3 @@ INSERT INTO volumes
     FROM volumes_backup;
 
 DROP TABLE volumes_backup;
-COMMIT;

cinder/db/sqlalchemy/migrate_repo/versions/007_sqlite_downgrade.sql

@@ -1,8 +1,6 @@
 -- As sqlite does not support the DROP FOREIGN KEY, we need to create
 -- the table, and move all the data to it.
 
-BEGIN TRANSACTION;
-
 CREATE TABLE snapshots_v6 (
     created_at DATETIME,
     updated_at DATETIME,
@@ -28,5 +26,3 @@ INSERT INTO snapshots_v6 SELECT * FROM snapshots;
 DROP TABLE snapshots;
 
 ALTER TABLE snapshots_v6 RENAME TO snapshots;
-
-COMMIT;

cinder/db/sqlalchemy/migrate_repo/versions/011_sqlite_downgrade.sql

@@ -1,5 +1,3 @@
-BEGIN TRANSACTION;
-
 CREATE TABLE volumes_v10 (
     created_at DATETIME,
     updated_at DATETIME,
@@ -61,4 +59,3 @@ INSERT INTO volumes_v10
 
 DROP TABLE volumes;
 ALTER TABLE volumes_v10 RENAME TO volumes;
-COMMIT;

cinder/db/sqlalchemy/migrate_repo/versions/012_sqlite_downgrade.sql

@@ -1,5 +1,3 @@
-BEGIN TRANSACTION;
-
 CREATE TABLE volumes_v11 (
     created_at DATETIME,
     updated_at DATETIME,
@@ -63,4 +61,3 @@ INSERT INTO volumes_v11
 
 DROP TABLE volumes;
 ALTER TABLE volumes_v11 RENAME TO volumes;
-COMMIT;

cinder/db/sqlalchemy/migrate_repo/versions/013_sqlite_downgrade.sql

@@ -1,5 +1,3 @@
-BEGIN TRANSACTION;
-
 CREATE TABLE volumes_v12 (
     created_at DATETIME,
     updated_at DATETIME,
@@ -65,4 +63,3 @@ INSERT INTO volumes_v12
 
 DROP TABLE volumes;
 ALTER TABLE volumes_v12 RENAME TO volumes;
-COMMIT;

cinder/db/sqlalchemy/migrate_repo/versions/014_sqlite_downgrade.sql

@@ -1,5 +1,3 @@
-BEGIN TRANSACTION;
-
 CREATE TABLE volumes_v13 (
     created_at DATETIME,
     updated_at DATETIME,
@@ -67,4 +65,3 @@ INSERT INTO volumes_v13
 
 DROP TABLE volumes;
 ALTER TABLE volumes_v13 RENAME TO volumes;
-COMMIT;