sql-server - 在WITH表达式中声明变量(SQL Server)？

Question

有没有办法在WITH表达式中定义变量？像这样的东西:

;WITH SomeName AS ( 
    declare @somevar decimal
    set @somevar = ...
    SELECT ....)

可能吗？

Answer 1

不，您需要在 CTE 之外声明/设置它

DECLARE @somevar DECIMAL
;WITH SomeName AS (SELECT....)
SELECT @somevar = ...
FROM SomeName

每MSDN :

CTE_query_definition
Specifies a SELECT statement whose result set populates the common table expression. The SELECT statement for CTE_query_definition must meet the same requirements as for creating a view, except a CTE cannot define another CTE.