根据联合结果从第三个表中选择

Question

我目前正在使用union运算符从两个表中选择材料：

QUERY

SELECT Material 
FROM (
       SELECT Material    
       FROM DP_Historical_Data 
       EXCEPT SELECT Material 
       FROM SAS_GLOBE_Material_to_SASBaseItem
     ) HD
 UNION SELECT Material 
 FROM (
        SELECT Material 
        FROM DP_Historical_Data_Archive 
        EXCEPT SELECT Material 
        FROM SAS_GLOBE_Material_to_SASBaseItem
      ) HDA

我现在要做的是使用检索到的材料从第三个表中获取描述，即：

Select MaterialDescription 
from Description_Table DT 
Where DT.Material = UnionResult.Material

这有什么整洁的方法吗？

Answer 1

Select UnionResult.Material, DT.MaterialDescription 
FROM Description_Table DT 
JOIN
(    
    SELECT Material FROM 
    (
       SELECT Material 
       FROM DP_Historical_Data 
       EXCEPT 
       SELECT Material 
       FROM SAS_GLOBE_Material_to_SASBaseItem
    ) HD
    UNION 
    SELECT Material 
    FROM 
    (
       SELECT Material 
       FROM DP_Historical_Data_Archive 
       EXCEPT 
       SELECT Material
       FROM SAS_GLOBE_Material_to_SASBaseItem
    ) HDA
) UnionResult ON DT.Material = UnionResult.Material

Answer 2

SELECT DT.MaterialDescription
FROM Description_Table DT
INNER JOIN (
    SELECT Material
    FROM (
        SELECT Material
        FROM DP_Historical_Data

        EXCEPT

        SELECT Material
        FROM SAS_GLOBE_Material_to_SASBaseItem
        ) HD

    UNION

    SELECT Material
    FROM (
        SELECT Material
        FROM DP_Historical_Data_Archive

        EXCEPT

        SELECT Material
        FROM SAS_GLOBE_Material_to_SASBaseItem
        ) HDA
    ) unires
WHERE DT.Material = unires.Material

Answer 3

CREATE VIEW UnionResult AS
    (
    SELECT Material FROM (SELECT Material FROM DP_Historical_Data EXCEPT SELECT Material
    FROM SAS_GLOBE_Material_to_SASBaseItem) HD
    UNION 
    SELECT Material FROM
         (SELECT Material FROM DP_Historical_Data_Archive EXCEPT SELECT Material FROM 
          SAS_GLOBE_Material_to_SASBaseItem) HDA
    )

Select MaterialDescription from Description_Table DT,UnionResult
Where DT.Material = UnionResult.Material