MySQL 如何计算MySQL产品表中产品的总价值?
首先让我们创建一个表 –
mysql> create table DemoTable
(
ProductId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
ProductQuantity int,
ProductPrice int
);
Query OK,0 rows affected(0.19 sec)
使用insert命令在表中插入一些记录 –
mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(10,100);
Query OK,1 row affected(0.06 sec)
mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(5,11);
Query OK,1 row affected(0.04 sec)
mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(3,140);
Query OK,1 row affected(0.05 sec)
mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(2,450);
Query OK,1 row affected(0.15 sec)
使用select语句显示表中的所有记录 –
mysql> select *from DemoTable;
这将产生以下输出 –
+-----------+-----------------+--------------+
| ProductId | ProductQuantity | ProductPrice |
+-----------+-----------------+--------------+
| 1 | 10 | 100 |
| 2 | 5 | 11 |
| 3 | 3 | 140 |
| 4 | 2 | 450 |
+-----------+-----------------+--------------+
4 rows in set (0.00 sec)
以下是计算产品总价值的查询 –
mysql> select sum(ProductQuantity*ProductPrice) as Total_of_Products from DemoTable;
这将产生以下输出 –
+-------------------+
| Total_of_Products |
+-------------------+
| 2375 |
+-------------------+
1 row in set (0.00 sec)
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