带有Lambda表达式的LINQ-连接，分组依据，总和和计数

Question

How can I "translate" this SQL query to Linq Lambda Expression:

    SELECT  BN.DEUF, 
            BN.DESUPERINTENDENCIAREGIONAL,
            CR.SITUACAODIVIDA, 
            COUNT(CR.VLEFETIVAMENTELIBERADO), 
            SUM(CR.VLEFETIVAMENTELIBERADO)
   FROM BENEFICIARIO BN
   JOIN CREDITO CR ON BN.CDBENEFICIARIO = CR.CDBENEFICIARIO
   GROUP BY BN.DEUF,BN.DESUPERINTENDENCIAREGIONAL, CR.SITUACAODIVIDA
   ORDER BY BN.DEUF

Until now I have:

var itens = db.CREDITO
            .Join(db.BENEFICIARIO, cr => cr.CDBENEFICIARIO, bn => bn.CDBENEFICIARIO,
                                (cr, bn) => new { cr, bn })
            .GroupBy(cr => cr.VLEFETIVAMENTELIBERADO)
            .Select(g => new { VLTOTAL = g.Sum(x => x.VLEFETIVAMENTELIBERADO) })
            .ToList();

Answer 1

You just don't do the same group by in your sql and your linq.

So... let's do it !

var itens = db.CREDITO
            .Join(db.BENEFICIARIO, cr => cr.CDBENEFICIARIO, bn => bn.CDBENEFICIARIO,(cr, bn) => new { cr, bn })
            .GroupBy(x=> new{x.bn.DEUF,x.bn.DESUPERINTENDENCIAREGIONAL, x.cr.SITUACAODIVIDA})
            .Select(g => new { 
                       g.Key.DEUF,
                       g.Key.DESUPERINTENDENCIAREGIONAL,
                       g.Key.SITUACAODIVIDA,
                       VLTOTAL = g.Sum(x => x.cr.VLEFETIVAMENTELIBERADO),
                       Count = g.Count() 
                       })
            .ToList();

Answer 2

You will have to create an anonymous type in Group By clause to group by multiple columns. This should work:-

var itens = db.CREDITO
            .Join(db.BENEFICIARIO, cr => cr.CDBENEFICIARIO, bn => bn.CDBENEFICIARIO,
                                (cr, bn) => new { cr, bn })
            .GroupBy(x => new { 
                                  x.cr.SITUACAODIVIDA, 
                                  x.bn.DEUF, 
                                  x.bn.DESUPERINTENDENCIAREGIONAL 
                              }
             )
            .Select(g => new { 
                                 DEUF = g.Key.DEUF,
                                 SITUACAODIVIDA = g.Key.SITUACAODIVIDA,
                                 VLTOTAL = g.Sum(z => z.cr.VLEFETIVAMENTELIBERADO),
                                 Count = g.Count()
                             }
                   ).ToList();