mysql高手帮忙看看,谢谢 把cast(fen1 as int)改为cast(fen1 as signed)就行了,即是把int改为signed 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 mysql> create table haha(id int,fen1 varchar(10),fen2 varchar(10),fen3 varchar(10));Query OK, 0 rows affected (0.38 sec)mysql>mysql> insert into haha values(1,'20','20','20');Query OK, 1 row affected (0.02 sec)mysql> insert into haha values(2,'20','30','40');Query OK, 1 row affected (0.03 sec)mysql> insert into haha values(3,'10','20','20');Query OK, 1 row affected (0.00 sec)mysql> select * from haha;+------+------+------+------+| id | fen1 | fen2 | fen3 |+------+------+------+------+| 1 | 20 | 20 | 20 || 2 | 20 | 30 | 40 || 3 | 10 | 20 | 20 |+------+------+------+------+3 rows in set (0.02 sec)mysql> select *,fen1+fen2+fen3 as fen from haha order by fen desc;+------+------+------+------+------+| id | fen1 | fen2 | fen3 | fen |+------+------+------+------+------+| 2 | 20 | 30 | 40 | 90 || 1 | 20 | 20 | 20 | 60 || 3 | 10 | 20 | 20 | 50 |+------+------+------+------+------+3 rows in set (0.00 sec) 谁能教我 MySQL GUI Tools 怎么用 mysql数据库服务器 关于MYSQL数据库的编码问题/求高手解答. 抓取网页,遇到一个入库问题,是关于字符集的。 请教一个mysql 的sql 语句写法 MySQL数据库问题(菜鸟类) >安装完MYSQL,如何用啊???< Mysql 删除表冗余数据——这个语句怎么写?? 急需求助(mysql) mysql vatchar(20) varchar(200)的区别 MySQL的参数问题 帮忙看看下面的语句,为什么pay和paytype这两张表不能创建
0));
Query OK, 0 rows affected (0.38 sec)mysql>
mysql> insert into haha values(1,'20','20','20');
Query OK, 1 row affected (0.02 sec)mysql> insert into haha values(2,'20','30','40');
Query OK, 1 row affected (0.03 sec)mysql> insert into haha values(3,'10','20','20');
Query OK, 1 row affected (0.00 sec)mysql> select * from haha;
+------+------+------+------+
| id | fen1 | fen2 | fen3 |
+------+------+------+------+
| 1 | 20 | 20 | 20 |
| 2 | 20 | 30 | 40 |
| 3 | 10 | 20 | 20 |
+------+------+------+------+
3 rows in set (0.02 sec)
mysql> select *,fen1+fen2+fen3 as fen from haha order by fen desc;
+------+------+------+------+------+
| id | fen1 | fen2 | fen3 | fen |
+------+------+------+------+------+
| 2 | 20 | 30 | 40 | 90 |
| 1 | 20 | 20 | 20 | 60 |
| 3 | 10 | 20 | 20 | 50 |
+------+------+------+------+------+
3 rows in set (0.00 sec)