SQL查询，我需要每人1行，最低Id为两列

Question

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

我有这个查询，它会返回以下结果：

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

在该查询和结果集中，如何使用;

为每人返回1行

1. 最低诊断ID及其描述
2. 具有desc和得分的最低类别ID。
3. 取代null类别，返回类别ID 1及其desc和得分。

Answer 1

尝试以下查询：

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