Question

I’m pretty new to MVC and the Entity Framework, but I’m sure this should be straight forward. I’ve got a class with a boolean “Active” flag. I then have a function that returns the results by date descending. All I want to do is ensure that only active records are returned. Should be simple, but it fails with the following error:

Error 13 Overload resolution failed because no accessible ‘Where’ can be called with these arguments:
Extension method ‘Public Function Where(predicate As System.Func(Of Review, Integer, Boolean)) As System.Collections.Generic.IEnumerable(Of Review)’ defined in ‘System.Linq.Enumerable’: Value of type ‘Boolean’ cannot be converted to ‘System.Func(Of PowellCasting.Models.Review, Integer, Boolean)’.
Extension method ‘Public Function Where(predicate As System.Func(Of Review, Boolean)) As System.Collections.Generic.IEnumerable(Of Review)’ defined in ‘System.Linq.Enumerable’: Value of type ‘Boolean’ cannot be converted to ‘System.Func(Of PowellCasting.Models.Review, Boolean)’.
Extension method ‘Public Function Where(predicate As System.Linq.Expressions.Expression(Of System.Func(Of Review, Integer, Boolean))) As System.Linq.IQueryable(Of Review)’ defined in ‘System.Linq.Queryable’: Value of type ‘Boolean’ cannot be converted to ‘System.Linq.Expressions.Expression(Of System.Func(Of PowellCasting.Models.Review, Integer, Boolean))’.
Extension method ‘Public Function Where(predicate As System.Linq.Expressions.Expression(Of System.Func(Of Review, Boolean))) As System.Linq.IQueryable(Of Review)’ defined in ‘System.Linq.Queryable’: Value of type ‘Boolean’ cannot be converted to ‘System.Linq.Expressions.Expression(Of System.Func(Of PowellCasting.Models.Review, Boolean))’. C:\Web Projects\Powell Casting\PowellCasting\PowellCasting\Models\Review.vb 42 14 PowellCasting

It looks as thought it doesn’t like comparing Booleans but they have the same data type. I’m sure this should be simple, but would appreciate some help. Please see my code below.

Public Class Review

Private PowellCastingDB As PowellCastingEntites = New PowellCastingEntites

<ScaffoldColumn(False)>
Public Property ReviewID As Integer
<Required(ErrorMessage:="An review title is required")>
<StringLength(256)>
<DisplayName("Title")>
Public Property Title As String
<DisplayName("Heading")>
Public Property Heading As String
<DisplayName("ReviewText")>
<StringLength(4096)>
Public Property ReviewText As String
<DisplayName("Author")>
<StringLength(256)>
Public Property Author As String
<DisplayName("Publication")>
<StringLength(150)>
Public Property Publication As String
<DisplayName("PublicationDate")>
Public Property PublicationDate As Date
<DisplayName("PublicationLink")>
<StringLength(1000)>
Public Property PublicationLink As String
<DisplayName("Image")>
<StringLength(512)>
Public Property Image As String
<DisplayName("Active")>
Public Property Active As Boolean

Public Property Reviews As List(Of Review)

Public Function GetLatestReviews(ByVal count As Integer) As List(Of Review)
  Return PowellCastingDB.Reviews.Where(Active = True).
  OrderByDescending(Function(a) a.PublicationDate).
   Take(count).
    ToList()
End Function

End Class
End Namespace

Answer 1

You need to specify a lambda expression:

Return PowellCastingDB.Reviews.Where(Function(x) x.Active = True).
    (rest of query)

Or just:

Return PowellCastingDB.Reviews.Where(Function(x) x.Active).
    (rest of query)