Question

在以下示例中，无法按Field_2（子查询）进行排序有解决办法吗？

SELECT *
FROM
(
    SELECT
    Field_A,
    (SELECT Field_1 FROM Table_2) AS Field_B,
    Field_C,
    ROW_NUMBER() OVER (ORDER BY Field_B ASC) AS Row_Num
    FROM Table_1
) AS Name
WHERE Row_Num BETWEEN 1 AND 100

Answer 1

您不能在与声明相同的select子句中使用别名。
您可以按照Zaynul Abadin Tuhin的答案中的说明重复子查询，也可以使用另一个派生表（或cte）：

SELECT *
FROM (
    SELECT *, ROW_NUMBER() OVER (ORDER BY Field_B ASC) AS Row_Num
    FROM
    (
        SELECT
        Field_A,
        (SELECT Field_1 FROM Table_2) AS Field_B,
        Field_C
        FROM Table_1
    ) AS Name
) As NumberedName
WHERE Row_Num BETWEEN 1 AND 100

另外，请注意，除非Table_2仅一行，否则将(SELECT Field_1 FROM Table_2)用作子查询将导致错误-

子查询返回了多个值。当子查询遵循=，！=，<，<=，>，> =或将子查询用作表达式时，不允许这样做。

Larnu在评论中指出。

Answer 2

您不能使用别名，必须按顺序使用该子查询

   with cte as (
        SELECT
        Field_A,
        (SELECT Field_1 FROM Table_2
        ) AS Field_B, --- it should have to rerun 1 value otherwise it will thrown error , so i think here need where condition
        Field_C       
        FROM Table_1
         ) , cte2 as    
         ( select *, row_number() over(order by Field_B asc) rn
           from cte
          ) select * from cte where rn>=1 and rn<=100

ROW_NUMBER（）问题与子查询

2 个答案: