MySQL主键自增

1. 查看自增值

SELECT Auto_increment
  FROM information_schema.TABLES
 WHERE Table_Schema= 'database'
   AND table_name= 'tableName'

2.设置自增值

alter table 'tableName' AUTO_INCREMENT=1;

3.重置自增值

truncate table `tableName`;

注意: delete table 并不会清空自增值, 如果delete table 需要再重新alter设置自增值