in case database has been dropped

Signed-off-by: Qun Li <qun.li@zstack.io>

Author: live4thee

conf/db/upgrade/beforeValidate.sql

@@ -1,5 +1,3 @@
-use zstack;
-
 -- Update `schema_version' since we've changed SQL to match the expectation
 -- of the newer version MariaDB.
 DELIMITER $$
@@ -8,12 +6,15 @@ DROP PROCEDURE IF EXISTS `update_schema_checksum` $$
 
 CREATE PROCEDURE `update_schema_checksum`()
 BEGIN
-    IF EXISTS(SELECT table_name FROM information_schema.tables WHERE table_name = 'schema_version')
+    IF EXISTS(SELECT schema_name   FROM information_schema.schemata  WHERE schema_name = 'zstack')
     THEN
-        update `schema_version` set `checksum`=1083194846  where `script`='V1.6__schema.sql'   and `checksum` <> 1083194846;
-        update `schema_version` set `checksum`=-1569422253 where `script`='V2.1.0__schema.sql' and `checksum` <> -1569422253;
-        update `schema_version` set `checksum`=1564279419  where `script`='V3.0.0__schema.sql' and `checksum` <> 1564279419;
-        update `schema_version` set `checksum`=565652311   where `script`='V3.7.2__schema.sql' and `checksum` <> 565652311;
+        IF EXISTS(SELECT table_name FROM information_schema.tables WHERE table_name = 'schema_version')
+        THEN
+            update `zstack`.`schema_version` set `checksum`=1083194846  where `script`='V1.6__schema.sql'   and `checksum` <> 1083194846;
+            update `zstack`.`schema_version` set `checksum`=-1569422253 where `script`='V2.1.0__schema.sql' and `checksum` <> -1569422253;
+            update `zstack`.`schema_version` set `checksum`=1564279419  where `script`='V3.0.0__schema.sql' and `checksum` <> 1564279419;
+            update `zstack`.`schema_version` set `checksum`=565652311   where `script`='V3.7.2__schema.sql' and `checksum` <> 565652311;
+        END IF;
     END IF;
 END $$