MySQL 5.5 INSERT ON DUPLICATE KEY UPDATE语句解说
发布时间：2022-04-11 18:33:22 所属栏目：MySql教程 来源：互联网
导读：执行INSERT ... ON DUPLICATE KEY UPDATE语句，如果INSERT的语句插入的值和已有的UNIQUE索引或主键重复的话，MySQL会更新已存在的行。 测试没有主键和UNIQUE索引的表 mysql select * from dept2; +--------+-------------+-------------+ | deptno | dname |
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执行INSERT ... ON DUPLICATE KEY UPDATE语句，如果INSERT的语句插入的值和已有的UNIQUE索引或主键重复的话，MySQL会更新已存在的行。 测试没有主键和UNIQUE索引的表 mysql> select * from dept2; +--------+-------------+-------------+ | deptno | dname | report_date | +--------+-------------+-------------+ | 10 | Research | 2016-06-03 | | 20 | Maintenance | 2016-06-03 | | 30 | Leader | 2016-06-03 | | 40 | Market | 2015-08-02 | +--------+-------------+-------------+ 4 rows in set (0.00 sec) mysql> desc dept2; +-------------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------------+-------------+------+-----+---------+-------+ | deptno | int(5) | NO | MUL | NULL | | | dname | varchar(14) | YES | | NULL | | | report_date | date | YES | MUL | NULL | | +-------------+-------------+------+-----+---------+-------+ 3 rows in set (0.00 sec) mysql> INSERT INTO dept2 (deptno,dname,report_date) VALUES (20,'Development','2010-10-30') -> ON DUPLICATE KEY UPDATE report_date='2010-10-30'; Query OK, 1 row affected (0.01 sec) mysql> select * from dept2; +--------+-------------+-------------+ | deptno | dname | report_date | +--------+-------------+-------------+ | 10 | Research | 2016-06-03 | | 20 | Maintenance | 2010-10-30 | | 30 | Leader | 2016-06-03 | | 40 | Market | 2015-08-02 | +--------+-------------+-------------+ 4 rows in set (0.00 sec) （编辑：东莞站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
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