mysql怎么实现列求和

mysql怎么实现列求和

使用聚合函数sum()对MySQL中列的元素求和。语法如下-

select sum(yourColumnName1) as anyVariableName1,sum(yourColumnName2) as anyVariableName2,sum(yourColumnName3) as anyVariableName3,............N from yourTableName;

为了理解上述语法，让我们创建一个表。以下是创建表的查询-

mysql> create table SumDemoOnColumns
   −> (
   −> First int,  
   −> Second int,
   −> Third int
   −> );

使用insert命令在表中插入一些数据。查询如下-

mysql> insert into SumDemoOnColumns values(10,20,30);
mysql> insert into SumDemoOnColumns values(40,50,60);
mysql> insert into SumDemoOnColumns values(70,80,90);
mysql> insert into SumDemoOnColumns values(100,110,120);

使用select语句显示表中的所有记录。查询如下-

mysql> select *from SumDemoOnColumns;

以下是输出-

以下是获取列总和的查询-

mysql> select sum(First) as First,sum(Second) as Second,sum(Third) as Third from SumDemoOnColumns;

以下是输出-