SQL Server EXCEPT

Question

这就是我所处的情况。我有一张包含人们信息的表格。其中一些是从另一个系统导入的，而另一些是手动导入的。我想要做的就是吸引所有人，但是如果有手动输入的记录和导入的记录，我想只选择导入的记录（因为它可能更新）。

这是我到目前为止所做的，但它似乎不起作用（它只返回手动输入的记录）：

SELECT --fields go here
FROM
        (
                SELECT PERSON_UID, instype
                FROM AdmitsInterfaceTable
                WHERE instype='M' --Manually entered people
            EXCEPT
                SELECT PERSON_UID, instype
                FROM AdmitsInterfaceTable
                WHERE instype='I' --Imported people
        ) P,
        AdmitsInterfaceTable A
     WHERE 
        P.PERSON_UID=A.PERSON_UID
        AND P.instype=A.instype

我感觉这不起作用，因为内部查询也拉入了instype列，但我想不出更好的方法来做到这一点。有什么建议吗？

Answer 1

 SELECT PERSON_UID, instype
    FROM AdmitsInterfaceTable a
    WHERE instype='I' --get all imported people            
 union -- plus all manuals who are not also imported
 SELECT PERSON_UID, instype
    FROM AdmitsInterfaceTable a
    WHERE instype='M' --Imported people
    and not exists (  -- without imported matches
     select * from FROM AdmitsInterfaceTable b
     WHERE instype='I' and b.person_uid = a.person_uid);

Answer 2

你可以尝试：

SELECT CASE WHEN b.person_UID is null THEN a.person_UID ELSE person_UID END, 
CASE WHEN b.person_UID is null THEN a.instype   ELSE instype   END
--and so forth through all the columns you want
FROM
(SELECT PERSON_UID, instype  -- add list of additional fields you need here
from AdmitsInterfaceTable  WHERE instype='M' ) A
LEFT JOIN
(SELECT PERSON_UID, instype  -- add list of additional fields you need here
from AdmitsInterfaceTable  WHERE instype='I' ) B on A.PERSON_UID = B.PERSON_UID

Answer 3

SELECT --fields go here
FROM AdmitsInterfaceTable A
 WHERE 
    P.PERSON_UID=A.PERSON_UID
    AND P.instype=A.instype
AND instype='M' --Manually entered people
AND person_uid not in (
SELECT PERSON_UID FROM AdmitsInterfaceTable
WHERE instype='I' --Imported people
)