LINQ凡在MAX

Question

我现在有这个LINQ声明：

from s in SubContentRevisions 
where s.SubContentID.Equals("e3f319f1-65cc-4799-b84d-309941dbc1da") 
&& s.RevisionNumber == (SubContentRevisions.Max(s1 => s1.RevisionNumber)) 
select s 

生成这个SQL（根据LINQPad）：

-- Region Parameters 
DECLARE @p0 UniqueIdentifier = 'e3f319f1-65cc-4799-b84d-309941dbc1da' 
-- EndRegion 
SELECT [t0].[SubContentRevisionID], [t0].[SubContentID], [t0].[RevisionNumber], [t0].[RevisionText], [t0].[CreatedDate], [t0].[ModifiedDate] 
FROM [SubContentRevision] AS [t0] 
WHERE ([t0].[SubContentID] = @p0) AND ([t0].[RevisionNumber] = ((
    SELECT MAX([t1].[RevisionNumber]) 
    FROM [SubContentRevision] AS [t1] 
    ))) 

我怎样才能使它产生这个SQL语句？我似乎无法找到任何相关的任何地方。 （我需要它的where子句添加到子查询）

-- Region Parameters 
DECLARE @p0 UniqueIdentifier = 'e3f319f1-65cc-4799-b84d-309941dbc1da' 
-- EndRegion 
SELECT [t0].[SubContentRevisionID], [t0].[SubContentID], [t0].[RevisionNumber], [t0].[RevisionText], [t0].[CreatedDate], [t0].[ModifiedDate] 
FROM [SubContentRevision] AS [t0] 
WHERE ([t0].[SubContentID] = @p0) AND ([t0].[RevisionNumber] = ((
    SELECT MAX([t1].[RevisionNumber]) 
    FROM [SubContentRevision] AS [t1] 
    WHERE [SubContentID] = @p0 -- **********Adds the where clause********** 
    ))) 

Answer 1

我想你想：

from s in SubContentRevisions 
where s.SubContentID.Equals("e3f319f1-65cc-4799-b84d-309941dbc1da") 
    && s.RevisionNumber == (SubContentRevisions.Where(s.SubContentID.Equals("...")) 
              .Max(s1 => s1.RevisionNumber)) 
select s 

，或者更明确：

var specificSubContents = SubContentRevisions.Where(s => 
       s.SubContentID.Equals("e3f319f1-65cc-4799-b84d-309941dbc1da") 

var query = from s in specificSubContents 
      where s.RevisionNumber = s.Max(s1 => s1.RevisionNumber) 
      select s; 

或者，这听起来像你实际上可以这样做：

var latest = (from s in SubContentRevisions 
       where s.SubContentID.Equals("e3f319f1-65cc-4799-b84d-309941dbc1da") 
       orderby s.RevisionNumber descending 
       select s).FirstOrDefault(); 

Answer 2

如何回合添加where子句的子查询（最大）：

from s in SubContentRevisions 
where s.SubContentID.Equals("e3f319f1-65cc-4799-b84d-309941dbc1da") 
    && s.RevisionNumber == (SubContentRevisions 
            .Where(s1 => s1.SubContentID.Equals(s.SubContentID)) 
            .Max(s1 => s1.RevisionNumber)) 
select s