최대 날짜를 찾아 중복 결과를 제거하려면 어떻게합니까?

Question

ReleaseHistory 및 IterationHistory 테이블에 ReleaseID 및 IterationID 당 여러 레코드가 있으므로이 쿼리에서 중복 결과가 있음을 알고 있습니다. dbo.ReleaseHistory 및 dbo.IterationHistory에서 최대 날짜가있는 레코드 만 선택하고 싶습니다. 이 쿼리에서 어떻게합니까? SQL 서버 2008

SELECT  dbo.Assignable.AssignableID AS ID, 
      dbo.EntityType.Abbreviation AS Entity, 
      dbo.General.Name, dbo.Assignable.Effort, 
      dbo.Assignable.EffortCompleted, 
      dbo.Assignable.EffortToDo, 
      dbo.EntityState.Name AS State, 
      dbo.ReleaseHistory.Name AS Release, 
      dbo.IterationHistory.Name AS Iteration, 
      dbo.General.CustomField3 AS [Scrum Team] 
FROM  dbo.Assignable INNER JOIN 
      dbo.General ON dbo.Assignable.AssignableID = 
      dbo.General.GeneralID INNER JOIN 
      dbo.EntityType ON dbo.General.EntityTypeID = 
      dbo.EntityType.EntityTypeID INNER JOIN 
      dbo.EntityState ON dbo.Assignable.EntityStateID = 
      dbo.EntityState.EntityStateID AND 
      dbo.EntityType.EntityTypeID = 
      dbo.EntityState.EntityTypeID INNER JOIN 
      dbo.ReleaseHistory ON dbo.Assignable.ReleaseID = 
      dbo.ReleaseHistory.ReleaseID INNER JOIN 
      dbo.IterationHistory ON 
      dbo.Assignable.IterationID = 
      dbo.IterationHistory.IterationID LEFT OUTER JOIN 
      dbo.CustomField ON dbo.General.CustomField3 = 
      dbo.CustomField.CustomFieldID 
WHERE  (dbo.Assignable.ProjectID = 4054) 
GROUP BY dbo.Assignable.AssignableID, 
      dbo.EntityType.Abbreviation, 
      dbo.General.Name, 
      dbo.Assignable.Effort, 
      dbo.Assignable.EffortCompleted, 
      dbo.Assignable.EffortToDo, 
      dbo.EntityState.Name, 
      dbo.ReleaseHistory.Name, 
      dbo.IterationHistory.Name, 
      dbo.General.CustomField3 

Answer 1

브라이언, 난 당신이 MS SQL에서이 일을하고 항상 ReleaseHistory 및 IterationHistory 테이블에서 적어도 하나 개의 레코드가있을 것입니다 즐겁게하고

. 가정이 정확하다면 CROSS APPLY를 사용하여 두 테이블 모두에서 상위 1 레코드를 얻을 수 있습니다.

SELECT 
    dbo.Assignable.AssignableID AS ID , 
    dbo.EntityType.Abbreviation AS Entity , 
    dbo.General.Name , 
    dbo.Assignable.Effort , 
    dbo.Assignable.EffortCompleted , 
    dbo.Assignable.EffortToDo , 
    dbo.EntityState.Name AS State , 
    Release , 
    Iteration , 
    dbo.General.CustomField3 AS [Scrum Team] 
FROM 
    dbo.Assignable 

    INNER JOIN dbo.General ON dbo.Assignable.AssignableID = dbo.General.GeneralID 
    INNER JOIN dbo.EntityType ON dbo.General.EntityTypeID = dbo.EntityType.EntityTypeID 
    INNER JOIN dbo.EntityState ON dbo.Assignable.EntityStateID = dbo.EntityState.EntityStateID 
     AND dbo.EntityType.EntityTypeID = dbo.EntityState.EntityTypeID 
    CROSS APPLY(SELECT TOP 1 name Release FROM ReleaseHistory WHERE ReleaseID = Assignable.ReleaseID ORDER BY MaxDateColumn) a 
    CROSS APPLY(SELECT TOP 1 name Iteration FROM IterationHistory WHERE IterationID = Assignable.IterationID ORDER BY MaxDateColumn) b 
    LEFT OUTER JOIN dbo.CustomField ON dbo.General.CustomField3 = dbo.CustomField.CustomFieldID 
WHERE 
    (dbo.Assignable.ProjectID = 4054) 
GROUP BY 
    dbo.Assignable.AssignableID , 
    dbo.EntityType.Abbreviation , 
    dbo.General.Name , 
    dbo.Assignable.Effort , 
    dbo.Assignable.EffortCompleted , 
    dbo.Assignable.EffortToDo , 
    dbo.EntityState.Name , 
    dbo.ReleaseHistory.Name , 
    dbo.IterationHistory.Name , 
    dbo.General.CustomField3