MySQL 在重复键忽略？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2366813/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
On duplicate key ignore?
提问by Good-bye
I'm trying to finish this query; my tag field is set to UNIQUE and I simply want the database to ignore any duplicate tag.
我正在尝试完成此查询；我的标签字段设置为 UNIQUE，我只是希望数据库忽略任何重复的标签。
INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c')
ON DUPLICATE KEY IGNORE '*the offending tag and carry on*'
or even this would be acceptable
甚至这是可以接受的
INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c')
ON DUPLICATE KEY UPDATE '*the offending tag and carry on*'
回答by thummper
Would suggest NOT using INSERT IGNORE as it ignores ALL errors (ie its a sloppy global ignore).
Instead, since in your example tagis the unique key, use:
建议不要使用 INSERT IGNORE，因为它会忽略所有错误（即它是一个草率的全局忽略）。相反，由于在您的示例中tag是唯一键，请使用：
INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c') ON DUPLICATE KEY UPDATE tag=tag;
on duplicate key produces:
在重复键上产生：
Query OK, 0 rows affected (0.07 sec)
查询正常，0 行受影响（0.07 秒）
回答by Byron Whitlock
Mysql has this handy UPDATE INTOcommand ;)
Mysql 有这个方便的UPDATE INTO命令；)
editLooks like they renamed it to REPLACE
编辑看起来他们将其重命名为 REPLACE
REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted
REPLACE 的工作方式与 INSERT 完全相同，不同之处在于如果表中的旧行与 PRIMARY KEY 或 UNIQUE 索引的新行具有相同的值，则在插入新行之前删除旧行
