如何从我的 MySQL 产品表中计算产品的总价值？
让我们首先创建一个表-
mysql> create table DemoTable ( ProductId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ProductQuantity int, ProductPrice int );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(10,100); mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(5,11); mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(3,140); mysql> insert into DemoTable(ProductQuantity,ProductPrice) values(2,450);
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)