MySQL 如何对每一行中的2个单元格进行乘法运算？

您可以在两个单元格之间使用乘法运算符（*）。语法如下：

SELECT yourColumnName1,yourColumnName2,
yourColumnName1*yourColumnName2 as ‘anyVariableName’
from yourTableName;

为了理解上述语法，让我们创建一个表。创建表的查询语句如下：

mysql> create table MultiplicationDemo
   -> (
   -> FirstPrice int,
   -> SecondPrice int
   -> );
Query OK, 0 rows affected (0.63 sec)

现在，您可以使用插入命令显示来自表的所有记录。查询语句如下：

mysql> insert into MultiplicationDemo values(10,2);
Query OK, 1 row affected (0.17 sec)

mysql> insert into MultiplicationDemo values(4,2);
Query OK, 1 row affected (0.30 sec)

mysql> insert into MultiplicationDemo values(5,6);
Query OK, 1 row affected (0.17 sec)

mysql> insert into MultiplicationDemo values(6,3);
Query OK, 1 row affected (0.12 sec)

使用select语句显示表中的所有记录。查询语句如下：

mysql> select *from MultiplicationDemo;

以下是输出

+------------+-------------+
| FirstPrice | SecondPrice |
+------------+-------------+
|           10 |            2 |
|            4 |            2 |
|            5 |            6 |
|            6 |            3 |
+------------+-------------+
4 rows in set (0.00 sec)

下面是对2个单元格进行乘法运算的查询：

mysql> select FirstPrice,SecondPrice,
   -> FirstPrice*SecondPrice as 'MultiplicationResult'
   -> from MultiplicationDemo;

以下是输出

+------------+-------------+----------------------+
| FirstPrice | SecondPrice | MultiplicationResult |
+------------+-------------+----------------------+
|           10 |            2 |                   20 |
|            4 |            2 |                    8 |
|            5 |            6 |                   30 |
|            6 |            3 |                   18 |
+------------+-------------+----------------------+
4 rows in set (0.03 sec)

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