如何合并两个或多个SELECT语句的输出?我有多个表格,它们都有一些数据需要提取,所以我编写了多个SELECT查询。现在我想要合并这些查询的结果,我应该怎么做?我希望输出结果如下:
t1.qty,t2.qty,t3.qty
t1.qty,t2.qty,t3.qty
一个选项是:
SELECT (SELECT SUM(qty) FROM Table1 WHERE ...),
(SELECT SUM(qty) FROM Table2 WHERE ...),
(SELECT SUM(qty) FROM Table3 WHERE ...)
如果有链接,另一个人也可以加入:
SELECT *
FROM (SELECT ID,SUM(qty) FROM Table1 GROUP BY ID) T1
JOIN (SELECT ID,SUM(qty) FROM Table2 GROUP BY ID) T2
ON T1.ID = T2.ID
JOIN (SELECT ID,SUM(qty) FROM Table3 GROUP BY ID) T3
ON T1.ID = T3.ID
上述选项将显示在一行中。
您可能需要使用联合来合并行:
SELECT qty FROM Table1
UNION
SELECT qty FROM Table2
UNION
SELECT qty FROM Table3
如果您定义更具体的需求,将会有更多的选项可供选择。
SELECT tableA.data1, tableB.data2 FROM tableA, tableB WHERE <condition here>
任务1 = "选择 top " & strmcount & " * from nregistration where " & strtotal1
任务2 = "选择 top " & strfcount & " * from nregistration where " & strtotal2
并行执行
UNION
吗? - Hanky PankyJOIN
.. - Radu Gheorghiu