sql - 在一个语句中使用多个 CTE

Question

我想在我的查询中使用多个 CTE，但我无法让它工作。以下是我想做的一个例子：

WITH tbl1 AS
    (SELECT *
    FROM tblStuff)

WITH tbl2 AS
    (SELECT tbl1.fldStuff1 ...
     FROM tbl1, tblStuff2)

    SELECT *
    FROM tbl2

Answer 1

您只需指定WITH一次。然后，您可以列出用逗号分隔的其他 CTE。例如：

WITH cte1 AS 
(
  ...
),
cte2 AS 
(
  ...
)
SELECT ...;

Answer 2

WITH tbl1 AS
    (SELECT *
    FROM tblStuff),

tbl2 AS
    (SELECT tbl1.fldStuff1, tbl1.fldStuff2, tblStuff2.fldStuff1, tblStuff2.fldStuff2
     FROM tbl1, tblStuff2)

    SELECT *
    FROM tbl2

当您使用多个 CTE 时，不需要额外的 WITH，用逗号分隔。