Question

我有两张桌子表1和2，如下图所示。我需要在结果表3中为表A中存在A和其对应的Act_rid的行插入Std_rid。我只在这里使用示例。我很困惑这里是否使用pivot或unpivot。任何帮助赞赏。感谢

  Table 1
 ----------
    G_Standard   N_Standard     Skill    One_for_all    Am_Water    B2Future    Std_rid

     ELW.6       Lit.W.K.6      Writing                   A                        1
     ELW.8       Lit.W.K.8      Writing                               A           2
     ELW.7       Lit.W.K.7      Writing        A                                   3

   Table 2
   ----------
  Act_rid     Act_Desc     date       createdby

    3         Am_Water     2/4/15     sys
    6         B2Future     2/4/15     sys
    1         One_for_all  2/14/15    sys


  Output Result Table 3
  ----------
     ID    Std_rid   Act_rid
     1        1        3
     2        2        6
     3        3        1

Answer 1

这是一个UNPIVOT。 UNPIVOT将列转换为行。

;WITH Unpivot_Table_1 AS (
    SELECT Std_rid,
        Act_Desc
    FROM [Table 1]
    UNPIVOT (Value FOR Act_Desc IN ([One_for_all],[Am_Water],[B2Future])) u
    WHERE u.Value = 'X'
)
SELECT ROW_NUMBER() OVER(ORDER BY t1.Std_rid) AS ID,
    t1.Std_rid,
    t2.Act_rid
FROM Unpivot_Table_1 t1
JOIN [Table 2] t2
    ON t2.Act_Desc = t1.Act_Desc;

我希望这是数据集成的东西。否则，你们都需要拍摄任何设计的人。

测试数据：

CREATE TABLE dbo.[Table 1]
(
  Std_rid INT NOT NULL PRIMARY KEY,
  One_for_all VARCHAR(1),
  Am_Water VARCHAR(1),
  B2Future VARCHAR(1)
);

INSERT INTO dbo.[Table 1] (Std_rid,One_for_all,Am_Water,B2Future)
VALUES
  (1,NULL,'X',NULL),
  (2,NULL,NULL,'X'),
  (3,'X',NULL,NULL);

CREATE TABLE dbo.[Table 2]
(
    Act_rid INT NOT NULL PRIMARY KEY,
    Act_Desc VARCHAR(30)
);

INSERT INTO dbo.[Table 2] (Act_rid,Act_Desc)
VALUES
    (3,'Am_Water'),
    (6,'B2Future'),
    (1,'One_for_all');

是否使用枢轴或非枢轴而没有任何聚合函数

1 个答案: