MySQL 表的约束-填充零

 CREATE TABLE `tt3` (
`a` int(5) unsigned zerofill DEFAULT NULL, --具有了zerofill
`b` int(5) unsigned DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=gbk ; 

-- 将a，b列的都新增值-1
mysql> select * from tt3;
+-------+------+
| a     | b    |
+-------+------+
| 00001 | 1    |
+-------+------+