我正在简化复杂的 select 语句,所以我想我会使用公用表表达式。
声明单个 cte 效果很好。
WITH cte1 AS (
SELECT * from cdr.Location
)
select * from cte1
是否可以在同一个 SELECT 中声明和使用多个 cte?
即这个sql给出了错误
WITH cte1 as (
SELECT * from cdr.Location
)
WITH cte2 as (
SELECT * from cdr.Location
)
select * from cte1
union
select * from cte2
错误是
Msg 156, Level 15, State 1, Line 7
Incorrect syntax near the keyword 'WITH'.
Msg 319, Level 15, State 1, Line 7
Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause, the previous statement must be terminated with a semicolon.
注意。我尝试输入分号并收到此错误
Msg 102, Level 15, State 1, Line 5
Incorrect syntax near ';'.
Msg 102, Level 15, State 1, Line 9
Incorrect syntax near ';'.
可能不相关,但这是在 SQL 2008 上。
最佳答案
我认为应该是这样的:
WITH
cte1 as (SELECT * from cdr.Location),
cte2 as (SELECT * from cdr.Location)
select * from cte1 union select * from cte2
基本上,WITH
只是这里的一个子句,与其他采用列表的子句一样,“,”是适当的分隔符。
关于sql - 如何在单个 SELECT 语句中拥有多个公用表表达式?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/584284/