mysql - 将 2 个表的总和插入一行

Question

我想在“总计”表的一行中存储从其他 2 个表计算的总和。

我想为每个表使用一列。

我尝试了以下方法:

INSERT INTO Totals(    Date,    FirstTableSum,    SecondTableSum)SELECT     '2010/01/31',    SUM( t.Data1 ),    SUM( v.Data2 )FROM    FirstTable as t,    SecondTable as vWHERE     t.Date = '2010/01/31'AND v.Date = '2010/01/31'

如果我进行查询以检查 2 个不同表的总和，我会得到不同的值。

SELECT SUM(Data1) FROM FirstTable WHERE Date='2010/01/31'/*The result is different from FirstTableSum: Why?*/SELECT SUM(Data2) FROM SecondTable WHERE Date='2010/01/31'/*The result is different from SecondTableSum Why?*/

我做错了什么？

谢谢

Answer 1

试试这个

SELECT 
 (SELECT SUM(Data1) FROM FirstTable WHERE Date=@date) FirstTableSum,
 (SELECT SUM(Data2) FROM SecondTable WHERE Date=@date) SecondTableSum