Question

表A：

parameter = request.GET['parameter']
parameter_1 = request.GET['parameter_1']
parameter_2 = request.GET['parameter_2']

表B：

ID   NAME
---------
1    ABC
2    XYZ

**我需要一些类似的结果表A的所有值均在表B中的表

ID   NAME   AID
----------------
1    ORANGE  1
2    APPLE   1
3    GUAVA   1
4    BANANA  2
5    CHICKO  2

Answer 1

看起来您只需要两个表之间的内部联接：

WITH cte AS (
    SELECT a.ID AS AID, a.NAME, b.ID AS BID,
        ROW_NUMBER () OVER (PARTITION BY a.ID ORDER BY b.ID) rn
    FROM tableA a
    INNER JOIN tableB b
        ON a.ID = b.AID
)

SELECT AID, NAME, BID
FROM cte
WHERE rn <= 2;

Answer 2

您可以使用内部联接

select a.*, b.id as bid
  from tableA a
  join tableB b on a.id = b.aid

Answer 3

尝试一下

----------SAMPLE DATA---------
    DECLARE @TABLEA as TABLE (ID INT, NAME VARCHAR(100))
    DECLARE @TABLEB AS TABLE (ID INT, NAME VARCHAR(100), AID INT)

    INSERT INTO @TABLEA VALUES (1, 'ABC'),(2,'XYZ')

    INSERT INTO @TABLEB VALUES (1, 'ORANGE', 1),(2, 'APPLE', 1),(3, 'GUAVA', 1),
    (4, 'BANANA', 2),(5, 'CHICKO', 2)

------------SOLUTION-----------------    
    ;WITH CTE AS
    (
    SELECT
        a.ID as AID,
        a.NAME,
        b.ID,
        ROW_NUMBER() OVER (PARTITION BY AID ORDER BY B.ID) as ROWNUMBER
    FROM @TABLEA A
    INNER JOIN @TABLEB B
        ON A.ID = B.AID
        )

    SELECT AID, NAME, ID FROM CTE WHERE ROWNUMBER<=2

Answer 4

您可以使用\left(解决此问题。我倾向于在加入之前：

row_number()

优化器可以为select a.*, b.id from tableA a join (select b.*, row_number() over (partition by aid order by b.id from tableB b ) b on a.id = b.aid where b.seqnum <= 2;和row_number()使用索引。

查询以获取具有限制的一对多记录

4 个答案: