在mysql中,可以利用聚合函數(shù)sum()對列中的元素進(jìn)行求和,該函數(shù)的作用就是返回指定列的總和,語法為“SELECT SUM(列名1) AS 列名1,SUM(列名2) AS 列名2 … FROM 表名;”。
本教程操作環(huán)境:windows10系統(tǒng)、mysql8.0.22版本、Dell G3電腦。
mysql怎么實(shí)現(xiàn)列求和
使用聚合函數(shù)sum()對MySQL中列的元素求和。語法如下-
select sum(yourColumnName1) as anyVariableName1,sum(yourColumnName2) as anyVariableName2,sum(yourColumnName3) as anyVariableName3,............N from yourTableName;
為了理解上述語法,讓我們創(chuàng)建一個(gè)表。以下是創(chuàng)建表的查詢-
mysql> create table SumDemoOnColumns ?> ( ?> First int, ?> Second int, ?> Third int ?> );
使用insert命令在表中插入一些數(shù)據(jù)。查詢?nèi)缦?
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語句顯示表中的所有記錄。查詢?nèi)缦?
mysql> select *from SumDemoOnColumns;
以下是輸出-
以下是獲取列總和的查詢-
mysql> select sum(First) as First,sum(Second) as Second,sum(Third) as Third from SumDemoOnColumns;
以下是輸出-
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