Equivalent of Group Join in Lambda Expression

Question

User-2089506584 posted

Hello,

What will be the equivalent GroupJoin lambda expression in LINQ when I do this.

            Dim fruit_salad = (From fruits In _DataContext_Fruits _
                                     Group Join fruitRipe In _DataContext_FruitRipe On fruitRipe.fID Equals fruits.fID Into Group
                                     From fruitty_lecious In Group.DefaultIfEmpty() _
                     Where fruits.FruitName = "Apple" _
                     Order By fruits.FruitName Desc _
                                     Select New With { _
                                         .FruitName = fruits.FruitName, _
                                         .FruitCheck = if(fruitty_lecious Is Nothing, False, True) _
                }).Where(Function(g) g.FruitCheck.Equals(True))

        
Lambda not so equivalent from above [:(]

            Dim fruit_salad = From fruits In _DataContext_Fruits _
                     .GroupJoin (???????)
                     .Where(Function(g) fruits.FruitName = "Apple") _
                     .GroupBy(Function(g) fruits.FruitName) _
                     .OrderBy(Function(g) a.Key) _
                     .Select(Function(g) New With {.Fruit = fruits.FruitName, .FruitCheck = if(fruitty_lecious Is Nothing, False, True)})

I hope you can help me. Thank You.

Answer 1

User-2089506584 posted

I have this C# GroupJoin but I can't convert this to VB.NET correctly [:(]

C#

           MedicalDataContext db = new MedicalDataContext();
            var query = db.Patients.GroupJoin(db.Claims,
                                              p => p.UnqPatientId,
                                              c => c.PatientId,
                                              (Patient, Claims) => new { Patient, Claims });

VB.NET

Dim db As New MedicalDataContext()
Dim query = db.Patients.GroupJoin(db.Claims, Function(p) p.UnqPatientId, Function(c) c.PatientId, Function(Patient, Claims) New With { _
    Patient, _
    Claims _
})

Answer 2

User1716267170 posted

Hi imperialx,

I use an online tool to convert the code from C# to VB, and it's exactly like what it looks now. Besides, the above code seems fine. Please show us the exact error message so that we can help you better.

Thnaks. 

Answer 3

User-2089506584 posted

Hi Wencui,

There is no intellisense for Function(c) c.PatientId, the field PatientId is missing. [:(]

-imperialx

Answer 4

User1716267170 posted

There is no intellisense for Function(c) c.PatientId, the field PatientId is missing.

 

Besides the intellisense, does the code work well? If not, what's the error message in compilation time? Thanks.

Answer 5

User-649019326 posted

I have this C# GroupJoin but I can't convert this to VB.NET correctly

C#

           MedicalDataContext db = new MedicalDataContext();
            var query = db.Patients.GroupJoin(db.Claims,
                                              p => p.UnqPatientId,
                                              c => c.PatientId,
                                              (Patient, Claims) => new { Patient, Claims });

VB.NET

Dim db As New MedicalDataContext()
Dim query = db.Patients.GroupJoin(db.Claims, Function(p) p.UnqPatientId, Function(c) c.PatientId, Function(Patient, Claims) New With { _
    Patient, _
    Claims _
})

Answer 6

User-1591218762 posted

Hi, I need convert a query to lambda, but I don't know. This is the query in VB:

Dim query = From c In Me.ObjectContext.Clientext

             Join uc In Me.ObjectContext.UsuarioCliente On c.idCompania Equals uc.idCompania And c.idCliente Equals uc.idCliente

             Where c.idCompania = UsuarioActual.Compania.idCompania And uc.Usuario = UsuarioActual.Usuario.Usuario
             Select c

Please, help me... Thanks!