SQL查询，我需要每人1行，最低Id为两列

我有一个查询，它返回以下结果：

SELECT 
    Mem.MemberID, Mem.LastName + ', ' + Mem.FirstName AS Name, 
    MD.DiagnosisID, 
    Diag.DiagnosisDescription, 
    DC.DiagnosisCategoryID, DC.CategoryDescription, DC.CategoryScore
FROM 
    Member AS Mem
LEFT OUTER JOIN 
    MemberDiagnosis AS MD ON Mem.MemberID = MD.MemberID
LEFT OUTER JOIN 
    Diagnosis AS Diag ON MD.DiagnosisID = Diag.DiagnosisID
LEFT OUTER JOIN 
    DiagnosisCategoryMap AS Map ON Map.DiagnosisID = Diag.DiagnosisID
LEFT OUTER JOIN 
    DiagnosisCategory AS DC ON DC.DiagnosisCategoryID = Map.DiagnosisCategoryID
ORDER BY 
    Name ASC

在该查询和结果集中，我如何才能使用

最低诊断ID及其描述

具有desc和score的最低类别ID

返回类别ID 1及其desc和score，而不是null category

---

请尝试以下查询：

ID  | Name          | D.ID | D.Desc         | C.ID | C. Desc     | C.Score
----+---------------+------+----------------+------+-------------+----------
2   | Smith, Jack   | NULL | NULL           | NULL | NULL        | NULL
1   | Smith, John   | 2    | Test Diagnosis | 2    | Category B  | 20
1   | Smith, John   | 4    | Test Diagnosis | 3    | Category C  | 30
3   | Smyth, Will   | 3    | Test Diagnosis | 3    | Category C  | 30
3   | Smyth, Will   | 4    | Test Diagnosis | 3    | Category C  | 30

---

答案因您的数据库供应商而异（MySQL有一个答案，其他人则有一个不同的答案）。您使用的是什么关系数据库管理系统？我使用的是MS SQL 2014。它几乎满足了我的需求。唯一的问题是，没有诊断的杰克没有出现在这个问题上。虽然它做了我需要它为另外两个做的事情。考虑到它应该拉的第一个左外连接，没有？@ShaneWorkman只需将

内连接

替换为

左连接

。我更新了我的答案，看看吧

SELECT T1.*,Diag2.DiagnosisDescription, DC2.CategoryDescription, DC2.CategoryScore 
FROM (SELECT DISTINCT 

    Mem.MemberID, Mem.LastName + ', ' + Mem.FirstName AS Name, 
    MIN(MD.DiagnosisID) OVER(PARTITION BY  Mem.MemberID) AS DiagnosisID, 

    MIN(ISNULL(DC.DiagnosisCategoryID,1)) OVER(PARTITION BY  Mem.MemberID) AS DiagnosisCategoryID
FROM 
    Member AS Mem
LEFT OUTER JOIN 
    MemberDiagnosis AS MD ON Mem.MemberID = MD.MemberID
LEFT OUTER JOIN 
    Diagnosis AS Diag ON MD.DiagnosisID = Diag.DiagnosisID
LEFT OUTER JOIN 
    DiagnosisCategoryMap AS Map ON Map.DiagnosisID = Diag.DiagnosisID
LEFT OUTER JOIN 
    DiagnosisCategory AS DC ON ISNULL(DC.DiagnosisCategoryID,1) = ISNULL(Map.DiagnosisCategoryID,1) ) AS T1 

LEFT JOIN   Diagnosis AS Diag2 ON T1.DiagnosisID = Diag2.DiagnosisID
LEFT JOIN   DiagnosisCategory AS DC2 ON T1.DiagnosisCategoryID = DC2.DiagnosisCategoryID
ORDER BY T1.NAME