CODEWITHSUNDEEP
vb.netlinq
Beldi Anouar
Beldi Anouar

Reputation: 2180

How to prevent error conversion from DBNull value to Decimal in Linq query results

I am trying to sum numeric values from a datatable using linq but because there are also null values in column UniteDispo I am getting an error:

Cannot cast DBNull.Value to type 'Decimal'. Please use a nullable type.

This is my code:

Dim query2 = (From order In tabDispoAnnee.AsEnumerable() _
    Where order.Field(Of Integer)("code_part") = tab.Rows(i).Item("code_part") And order.Field(Of Integer)("CodeTypeBien") = tab.Rows(i).Item("CodeTypeBien") _
    Group order By order!code_part, order!CodeTypeBien _
    Into unit = Sum(CDec(order("UniteDispo"))), ca = Sum(CDec(order("CADispo"))) _
    Select unit, ca).ToList

What is the proper syntax to overcome this error?

Upvotes: 2

Views: 857

Answers (1)

djv
djv

Reputation: 15772

Add a Where clause to filter out records with NULL value. Try this

Dim query2 = (From order In tabDispoAnnee.AsEnumerable() _
    Where order.Field(Of Integer)("code_part") = tab.Rows(i).Item("code_part") _ 
    And order.Field(Of Integer)("CodeTypeBien") = tab.Rows(i).Item("CodeTypeBien") _
    And order.Field(Of Integer?)("UniteDispo").HasValue _
    And order.Field(Of Double?)("CADispo").HasValue _
    Group order By order!code_part, order!CodeTypeBien _
    Into unit = Sum(CDec(order("UniteDispo"))), ca = Sum(CDec(order("CADispo"))) _
    Select unit, ca).ToList

Upvotes: 1

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