Linq to DataSet Left Join

Hello

Once again with a linq query problem...
The query works but only retrieve the joined rows, i want to retrieve all rows in the first datatable.

My current query:

vb.net Code:

Dim q = From regE In (From registoE In _dtRegistosAEnviar.AsEnumerable
               Group registoE By colaborador = registoE.Field(Of String)("Colaborador") Into grupoE = Group
               Select New With {
                   .Colaborador = colaborador,
                   .Seg = grupoE.Sum(Function(registoE) registoE.Field(Of Decimal)("Seg"))
               }).AsEnumerable,
               regS In (From registoS In _dtRegistosEnviados.AsEnumerable
               Group registoS By colaborador = registoS.Field(Of String)("Colaborador") Into grupoS = Group
               Select New With {
                   .Colaborador = colaborador,
                   .Seg = grupoS.Sum(Function(registoS) registoS.Field(Of Decimal)("Seg"))
               }).AsEnumerable
               Where (regE.Colaborador = regS.Colaborador)

This was the first result when I Googled:

http://www.codeguru.com/columns/vb/article.php/c15057

Thanks JMC

But that doesn't work, i already tested two different ways, the first one, that was similar to that one in Codeguru, the INTO clause after the Equals isn't recognized, i used this in here. Then i looked to another page at MSDN doesn't know which one and change the query to the one that i wrote...

Hmmm... I didn't, and don't right now, have the time to experiment and I've never done it before myself. I'll try later in the day if you still need it then.

Thanks but the join problem it's kind of solved.
Now i have other problem, and i don't know what to do. In the selected rows of the join, if i put only the fields of the left table, the query works fine, but if i put the row that i need from the right table, when the table don't have values for the matching it raises a nullexception.

I already tried to check if the value is nothing, but without luck.

Here's the code:

vb.net Code:

Dim query = From regE In (From registoE In _dtRegistosAEnviar.AsEnumerable
           Group registoE By colaborador = registoE.Field(Of String)("Colaborador") Into grupoE = Group
           Select New With {
               .Colaborador = colaborador,
               .Seg = grupoE.Sum(Function(registoE) registoE.Field(Of Decimal)("Seg"))
           }).AsEnumerable
           Group Join regS In (From registoS In _dtRegistosEnviados.AsEnumerable
           Group registoS By colaborador = registoS.Field(Of String)("Colaborador") Into grupoS = Group
           Select New With {
               .ColaboradorS = colaborador,
               .SegS = grupoS.Sum(Function(registoS) registoS.Field(Of Decimal?)("Seg"))
           }).AsEnumerable
           On regE.Colaborador Equals regS.ColaboradorS Into juncao = Group
            From ele In juncao.DefaultIfEmpty
            Select New With {
               .Colaborador = regE.Colaborador,
               .HorasPorLancar = regE.Seg,
               .TheErrorColum= ele.SegS <<<<<<<<<  ERROR >>>>>>>
            }

If i remove the line that throws the exception it works fine and i have all the values, but when i put this error column it throws the exception.

I already tried this

vb.net Code:

IIf(ele.SegS Is Nothing, 0, ele.SegS)

and this

vb.net Code:

If(ele.SegS Is Nothing, 0, ele.SegS)

and this

vb.net Code:

IIf(IsDBNull(ele.SegS), 0, ele.SegS)

and this

vb.net Code:

If(IsDBNull(ele.SegS), 0, ele.SegS)