联合查询的结果顺序

小编典典

联合查询的结果顺序

sql

我有一个联合查询，它从两个不同的总体中获取计数。如何强制结果按查询中写入的顺序而不是升序/降序返回？

select count(datediff(yyyy,dob,admitdate) as counts
from myTable
where condition
union
select count(datediff(yyyy,dob,admitdate) as counts
from myTable
where condition

我希望第一个结果始终作为第一行返回。这可能吗？

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2021-04-14

共1个答案

小编典典

您必须使用ORDER BY子句指定订单。在您的示例中，您可以执行以下操作：

SELECT 1 AS seq, COUNT(datediff(yyyy,dob,admitdate) as counts
  FROM myTable
 WHERE ...condition-1...
UNION
SELECT 2 AS seq, COUNT(datediff(yyyy,dob,admitdate) as counts
  FROM myTable
 WHERE ...condition-2...
 ORDER BY seq

2021-04-14