Question

这个问题是基于我之前的问题

SQL server 2008 R2, select one value of a column for each distinct value of another column

关于SQL Server 2008上的CTE。

   WITH my_cte(id_num, rn) AS (
      SELECT name, 
      rn = ROW_NUMBER() OVER (PARTITION BY a.name ORDER BY newid())
            FROM my_table as a
      )
   SELECT id_num FROM my_cte WHERE rn = 1

   INSERT INTO #temp_table 
   SELECT a.address from another_table as a,
            id_num from my_cte  -- here, I got error!!!

为什么我收到错误：关键字＆＃39;来自＆＃39;。

附近的语法不正确

我需要一个新表，其中包含来自another_table的一列和来自my_cte的一列。

e.g。

 address (from another_table)    id_num (from my_cte)
  city_1                        65 
  city_1                        36
  city_2                        65
  city_2                        36
  city_3                        65
  city_3                        36

我应该使用哪种连接来获取上表，以便每个地址都与CTE中的所有id_num相关联？假设id_num只有65和36两个值。 my_cte没有地址栏。

任何帮助都将不胜感激。

Answer 1

CTE只能在其后面的语句中使用。执行SELECT id_num FROM my_cte WHERE rn = 1后，cte不再存在。

Answer 2

CTE仅存在于单个查询中。但您可以将其与insert以及select：

一起使用

   WITH my_cte(id_num, rn) AS (
      SELECT name, ROW_NUMBER() OVER (PARTITION BY a.name ORDER BY newid()) as rn
      FROM my_table as a
   )
   INSERT INTO #temp_table 
       SELECT a.address, id_num
       from another_table as a JOIN
            my_cte
            on a.name = my_cte.name;

SELECT语句中的SQL 2008 R2 CTE语法错误

2 个答案: