多个子查询

Question

我可以在一个查询中使用多个WITH子查询吗？

;WITH x AS (
  SELECT ...
),
WITH y AS (
  SELECT ...
)
SELECT * FROM z 
INNER JOIN x ON ...
INNER JOIN y ON ...

Answer 1

它被称为common table expression，是的，您可以使用多个CTE，只使用一个WITH并删除第二个with，如下所示：

WITH x AS (
  SELECT ...
),y AS (
  SELECT ...
)
SELECT * FROM z 
INNER JOIN x ON ...
INNER JOIN y ON ...