让我们首先创建一个表-mysql> create table DemoTable
-> (
-> NumberOfItems int,
-> Amount int
-> );
使用插入命令在表中插入一些记录-mysql> insert into DemoTable values(4,902);
mysql> insert into DemoTable values(5,1000);
mysql> insert into DemoTable values(3,80);
使用select语句显示表中的所有记录-mysql> select *from DemoTable;
输出结果+---------------+--------+
| NumberOfItems | Amount |
+---------------+--------+
| 4 | 902 |
| 5 | 1000 |
| 3 | 80 |
+---------------+--------+
3 rows in set (0.00 sec)
以下是数据库操作的查询-mysql> select NumberOfItems,Amount,(NumberOfItems*Amount) AS PayableAmount from DemoTable;
输出结果+---------------+--------+---------------+
| NumberOfItems | Amount | PayableAmount |
+---------------+--------+---------------+
| 4 | 902 | 3608 |
| 5 | 1000 | 5000 |
| 3 | 80 | 240 |
+---------------+--------+---------------+
3 rows in set (0.00 sec)