如何组合来自两个 SQL 查询的结果？

Question

如何合并两个 SQL 查询的结果？

第一次查询：

Select T.NUM1,T.AM1
FROM
(
    Select Number AS NUM1,SUM(AMOUNT) As AM1 FROM TBLSALES WHERE NUMBER<20 GROUP BY NUMBER
)T

第二次查询

SELECT B.NUM2,B.AM2
FROM
(
    SELECT Number AS NUM2,SUM(AMOUNT) As AM2 FROM TBLSALES WHERE NUMBER>19 AND NUMBER<40 GROUP BY NUMBER
)B

Answer 1

只要列数和类型相同，UNION 或 UNION ALL 就可以工作。

Select T.NUM1 as NUM,T.AM1 as AM
FROM
(
    Select Number AS NUM1,SUM(AMOUNT) As AM1 FROM TBLSALES WHERE NUMBER<20 GROUP BY NUMBER
)T

UNION

SELECT B.NUM2 as NUM,B.AM2 as AM
FROM
(
    SELECT Number AS NUM2,SUM(AMOUNT) As AM2 FROM TBLSALES WHERE NUMBER>19 AND NUMBER<40 GROUP BY NUMBER
)B

Answer 2

您可以使用 UNION 来合并查询结果。 如果您想避免重复记录，您应该使用 UNION，如果您不想排除重复结果，请在这种情况下使用 UNION ALL。