CTE语法问题

Question

以下代码有什么问题？

WITH CTE2 AS
(
select 1 as id
union
select 2
),
with CTE3 AS
(
    select * from CTE2
)
select * from CTE3

失败，语法错误。

Answer 1

不需要第二个WITH

;WITH CTE2 AS
(
  select 1 as id
  union
  select 2
), CTE3 AS
(
   select * from CTE2
)
select * 
from CTE3;

Answer 2

您的代码中不需要额外的$key = substr(md5('mylittlepony').sha1('flutershyismylove'), 0, 31);。

使用多个CTE时，您可以用逗号分隔它们，不需要多个WITH。

WITH