[多封面图][修改]:sql修改

mallinkAdmin/src/main/resources/db/migration/V201905171447__ADD_COUPON_COVER_IMG.sql

@@ -4,4 +4,4 @@
 ALTER TABLE wx_coupon
 	ADD COLUMN `cover_picture` json DEFAULT null COMMENT '多封面图' after `cover_img`;
 
-UPDATE wx_coupon SET cover_picture=json_array(cover_img);
+UPDATE wx_coupon SET cover_picture=json_array(cover_img) WHERE cover_picture is null;

mallinkAdmin/src/main/resources/db/migration/V201905171614__ADD_CAMPAIGN_COVER_PICTURE.sql

@@ -4,4 +4,4 @@
 ALTER TABLE wx_campaign
 	ADD COLUMN `cover_picture` json DEFAULT null COMMENT '多封面图' after `cover_img`;
 
-UPDATE wx_campaign SET cover_picture=json_array(cover_img);
+UPDATE wx_campaign SET cover_picture=json_array(cover_img) WHERE cover_picture is null;

mallinkAdmin/src/main/resources/db/migration/V201905171621__ADD_TOPIC_COVER_PICTURE.sql

@@ -4,4 +4,4 @@
 ALTER TABLE wx_topic
 	ADD COLUMN `cover_picture` json DEFAULT null COMMENT '多封面图' after `cover`;
 
-UPDATE wx_topic SET cover_picture=json_array(cover);
+UPDATE wx_topic SET cover_picture=json_array(cover) WHERE cover_picture is null;