如何获取MySQL的另一列中每个不同值的总和？
您可以SUM()使用GROUPBY命令的聚合函数来获取另一列中每个不同值的总和。为了理解上述概念，让我们创建一个表。创建表的查询如下：
mysql> create table SumOfEveryDistinct -> ( -> Id int not null, -> Amount int -> );
使用insert命令在表中插入一些记录。查询如下：
mysql> insert into SumOfEveryDistinct values(10,100); mysql> insert into SumOfEveryDistinct values(11,200); mysql> insert into SumOfEveryDistinct values(12,300); mysql> insert into SumOfEveryDistinct values(10,400); mysql> insert into SumOfEveryDistinct values(11,500); mysql> insert into SumOfEveryDistinct values(12,600); mysql> insert into SumOfEveryDistinct values(10,700); mysql> insert into SumOfEveryDistinct values(11,800); mysql> insert into SumOfEveryDistinct values(12,900);
使用select语句显示表中的所有记录。查询如下：
mysql> select *from SumOfEveryDistinct;
以下是输出：
+----+--------+ | Id | Amount | +----+--------+ | 10 | 100 | | 11 | 200 | | 12 | 300 | | 10 | 400 | | 11 | 500 | | 12 | 600 | | 10 | 700 | | 11 | 800 | | 12 | 900 | +----+--------+ 9 rows in set (0.00 sec)
这是求和另一列中每个不同值的查询：
mysql> select Id, sum(Amount) as TotalSum from SumOfEveryDistinct -> group by Id;
以下是输出：
+----+----------+ | Id | TotalSum | +----+----------+ | 10 | 1200 | | 11 | 1500 | | 12 | 1800 | +----+----------+ 3 rows in set (0.00 sec)