84669 person learning
152542 person learning
20005 person learning
5487 person learning
7821 person learning
359900 person learning
3350 person learning
180660 person learning
48569 person learning
18603 person learning
40936 person learning
1549 person learning
1183 person learning
32909 person learning
INSERT INTO `demo` (id,name,value) SELECT 1,2,4 from DUAL WHERE NOT EXISTS (SELECT * FROM `demo` WHERE id=1 AND name=2) LIMIT 1;
我想把from DUAL 去掉可以实现我上面的功能,各位朋友有什么解决办法吗?
注:不允许建主键和约束,会约束到设计。
ringa_lee
(id, name)上建唯一索引,
insert ignore demo values (1, 2, 4);
(id, name)上建唯一索引,