如题。
示例
建表:
create table test_table (
`id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
name varchar(32) not null,
PRIMARY KEY (`id`),
UNIQUE KEY uk_name(`name`)
) engine = InnoDB character set = utf8mb4;
插入数据:
insert into test_table(name) values('aaa');
insert into test_table(name) values('aaa'); -- 会报错 Duplicate entry 'aaa' for key 'uk_name'
insert into test_table(name) values('bbb');
查询数据:
mysql> select * from test_table;
+----+------+
| id | name |
+----+------+
| 1 | aaa |
| 3 | bbb |
+----+------+
2 rows in set
可以看到 id 2 因为唯一索引冲突被消耗掉了。