Question

I have a LINQ2Entity problem, I want to get the value, string, from a database, so I select FProducts.Serial_number, and to end the query, I do .ToDictionary.

The problem is, it tells me that it doesn’t have sufficient parameters, to convert ToDictionary.

So I need something like select FProducts.Serial_number, Nothing). ToDictionary.
Also FProducts.Serial_number, 0).ToDictionary doesn’t work.

Any recommendations?

Sub GetStatistics(ByVal ProductNumbers As List(Of String), ByRef Passed As Integer, ByRef FailedProducts As List(Of String))
        Passed = 0
        FailedProducts = Nothing
        Dim tpDictionary As Dictionary(Of String, Integer)
        For Each productNumber As String In ProductNumbers
            Using context As New SelmaEntities
                Dim Table = (From GoodProducts In context.TestResults
                            Where (GoodProducts.Art_no = productNumber)
                            Select GoodProducts.Art_no, GoodProducts.Failed)
                tpDictionary = (From FProducts In context.TestResults
                            Where (FProducts.Art_no = productNumber And FProducts.Failed <> 0)
                            Order By FProducts.Serial_number
                            Select FProducts.Serial_number, ).ToDictionary

            End Using
        Next
    End Sub

Answer 1

ToDictionary requires lambda expressions as parameters: one to select the dictionary key, one to select the value. So try:

tpDictionary = (From FProducts In context.TestResults
                 Where (FProducts.Art_no = productNumber And FProducts.Failed <> 0))
               .ToDictionary(Function(p) FProducts.Serial_number, Function(p) 0)