sql - 选择从 CTE 使用 AS？ SQL Server 2008

Question

我正在尝试将 PostgreSQL 转换为 SQL Server。但是这个查询不起作用。

我究竟做错了什么？我试图在 WITH 之前添加一个分号，但没有运气。

   SELECT 
      member_a AS you, member_b AS mightknow, shared_connection,
      CASE
         WHEN (n1.member_job_country = n2.member_job_country AND n1.member_job_country = n3.member_job_country) THEN 'country in common'
         WHEN (n1.member_unvan_id = n2.member_unvan_id AND n1.member_unvan_id = n3.member_unvan_id) THEN 'unvan in common'
         ELSE 'nothing in common'
      END AS reason
   FROM (
      WITH transitive_closure(member_a, member_b, distance, path_string, direct_connection) AS
        (SELECT 
             member_a, member_b, 1 AS distance,
             CAST(member_a as varchar(MAX)) + '.' + CAST(member_b as varchar(MAX)) + '.' AS path_string,
             member_b AS direct_connection
         FROM Member_Contact_Edges
         WHERE member_a = 45046 -- set the starting node

         UNION ALL

         SELECT 
             tc.member_a, e.member_b, tc.distance + 1,
             CAST(tc.path_string as varchar(MAX)) + CAST(e.member_b as varchar(MAX)) + '.' AS path_string,
             tc.direct_connection
         FROM Member_Contact_Edges AS e
         JOIN transitive_closure AS tc ON e.member_a = tc.member_b
         WHERE tc.path_string NOT LIKE '%' + CAST(e.member_b as varchar(MAX)) + '.%'
         AND tc.distance < 2
        )

   SELECT
       member_a, member_b,direct_connection AS shared_connection
   FROM transitive_closure
   WHERE distance = 2
  ) AS youmightknow
  LEFT JOIN Members AS n1 ON youmightknow.member_a = n1.memberID
  LEFT JOIN Members AS n2 ON youmightknow.member_b = n2.memberID
  LEFT JOIN Members AS n3 ON youmightknow.shared_connection = n3.memberID
  WHERE (n1.member_job_country = n2.member_job_country 
         AND n1.member_job_country = n3.member_job_country)
        OR (n1.member_unvan_id = n2.member_unvan_id 
            AND n1.member_unvan_id = n3.member_unvan_id);

我得到的错误:

Msg 156, Level 15, State 1, Line 11
Incorrect syntax near the keyword 'WITH'.
Msg 319, Level 15, State 1, Line 11
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.
Msg 102, Level 15, State 1, Line 34
Incorrect syntax near ')'.

这是引用; Graphs in the Database - SQL Meets Social Networks - 查看文章底部的 facebook 建议部分。

提前致谢

Answer 1

CTE 声明需要放在顶部。您还可以使用逗号声明和连接多个 CTE，而不是混合 CTE 和派生表。

尝试

;WITH 
/*First CTE declaration*/
transitive_closure(member_a, member_b, distance, path_string, direct_connection) 
AS
(   
     ...
),
/*Second CTE declaration*/
youmightknow AS
(
SELECT member_a, member_b,direct_connection AS shared_connection
FROM transitive_closure
WHERE distance = 2
)        
SELECT member_a AS you,
...
FROM youmightknow