我的表结构:
CREATE TABLE `userimageview` (
`user_id` int(11) unsigned NOT NULL,
`image_id` int(11) unsigned NOT NULL,
`thumbnail_view` int(10) unsigned NOT NULL,
`fullsize_view` int(10) unsigned NOT NULL,
`point` int(10) unsigned NOT NULL,
KEY `everything` (`user_id`,`image_id`,`thumbnail_view`,`fullsize_view`,`point`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
我要添加的索引:
ALTER TABLE `userimageview` ADD UNIQUE `user_image` (`user_id` , `image_id`)
结果:
#1062 - Duplicate entry '1-11' for key 'user_image'
我应该如何添加UNIQUE
索引?
答案 0 :(得分:11)
您新添加的UNIQUE
约束失败,因为您的表已经包含违反它的重复行。使用如下查询找到约束违反者。只要这些行存在,您将无法添加UNIQUE
索引。
SELECT
user_id,
image_id,
COUNT(*) AS dupes
FROM userimageview
GROUP BY user_id, image_id
HAVING dupes > 1
ORDER BY dupes DESC