Linq自连接复合键

Question

请有人可以帮助我这个。

我有一张需要加入自己的表格。该表包含一个复合键。到目前为止，下面的SQL语句工作正常。

select * from releases as a inner join 
(
select * from releases as r1 
where id=50 
) as x 
on (a.ParentSeriesId = x.SeriesId and a.ParentPeriod = x.Period) OR a.id=50 

问题是如何将其转换为linq。

我所推出了迄今

from a in Releases 
join x in (
     (from r1 in Releases 
     where 
     r1.Id == 50 
     select new { 
     r1 
     })) 
     on new { a.ParentSeriesId, a.ParentPeriod, a.Id } 
    equals new { ParentSeriesId = x.r1.SeriesId, ParentPeriod = x.r1.Period, Id = 50 } 
select new{ 

} 

但是，这会产生下面的SQL语句

SELECT NULL AS [EMPTY] 
FROM [Releases] AS [t0] 
INNER JOIN [Releases] AS [t1] ON ([t0].[ParentSeriesId] = [t1].[SeriesId]) AND ([t0].[ParentPeriod] = [t1].[Period]) AND ([t0].[Id] = @p0) 
WHERE [t1].[Id] = @p1 

的问题是如何管理，使其为我原来的SQL语句。谢谢！！

Answer 1

的LINQ仅支持等值连接，因为你有一个OR“从”条款

var xQuery = from r in Releases 
      where r.Id == 50 
      select r; 

var query = from r in Releases 
      from x in xQuery 
      where (r.ParentSeriesId == x.SeriesId && r.ParentPeriod == x.Period) || 
        r.Id == 50 //r.Id == x.Id 
      select new 
      { 

      }