细节问题：ZEROFILL的用法范围。

mysql> CREATE TABLE t1 (year YEAR(4), month INT(2) UNSIGNED ZEROFILL,
-> day INT(2) UNSIGNED ZEROFILL);
Query OK, 0 rows affected (0.11 sec)

mysql> INSERT INTO t1 VALUES(2000,1,1),(2000,1,20),(2000,1,30),(2000,2,2)
-> (2000,2,23),(2000,2,23);
Query OK, 6 rows affected (0.03 sec)
Records: 6 Duplicates: 0 Warnings: 0

mysql> select * from t1;
+------+-------+------+
| year | month | day |
+------+-------+------+
| 2000 | 01 | 01 |
| 2000 | 01 | 20 |
| 2000 | 01 | 30 |
| 2000 | 02 | 02 |
| 2000 | 02 | 23 |
| 2000 | 02 | 23 |
+------+-------+------+
6 rows in set (0.02 sec)

DELIMITER $$

DROP PROCEDURE IF EXISTS `test`.`sp_zerofill`$$

CREATE PROCEDURE `test`.`sp_zerofill`(IN num int)
BEGIN
declare i int default 1;
-- initialization value
set @sqltext = 'insert into lk14 values(0,''char0'')';
-- begin while
while i < num do
set @sqltext = concat(@sqltext,',','(',i,',''char',ceil(num*rand()),''')');
set i = i + 1;
end while;
-- begin dynamic sql
prepare s1 from @sqltext;
execute s1;
deallocate prepare s1;
END$$

DELIMITER ;

call sp_zerofill(6);

select * from lk14 order by id;