EF query hits database more than one time - vb.net

Question

maybe is a simple issue but I'm pretty new to EF so:
I have this query:
Dim InvoicesQuery = (From i As Invoice In dbContext.Invoices.AsNoTracking() Where i.InvoiceNumber = -1
Select New InvoicesWithDetails With {
.InvoiceDetails = i.InvoicesDetails,
.InvoiceDetailsUnmerged = i.InvoicesDetailsUnmergeds,
.Examination = Nothing,
.Applicant = Nothing,
.InvoiceNumber = i.InvoiceNumber,
.InvoiceYear = i.InvoiceYear,
.DocCode = i.DocCode,
.CompanyId = i.CompanyId,
.InvoiceDate = i.InvoiceDate,
.NetAmount = i.NetAmount,
.AmountPaid = i.AmountPaid,
.AmountToPay = i.AmountToPay,
.VAT = i.VAT,
.AdditionalTax = i.AdditionalTax,
.Status = i.Status,
.Amount = i.Amount,
.ExaminationId = i.ExaminationId,
.ReceiverName = If(i.OtherReceiverName Is Nothing, i.ReceiverName, i.OtherReceiverName),
.ReceiverAddress = If(i.OtherReceiverAddress Is Nothing, i.ReceiverAddress, i.OtherReceiverAddress),
.ReceiverCity = If(i.OtherReceiverCity Is Nothing, i.ReceiverCity, i.OtherReceiverCity),
.ReceiverTaxCode = If(i.OtherReceiverTaxCode Is Nothing, i.ReceiverTaxCode, i.OtherReceiverTaxCode),
.ReceiverCompanyTaxCode = i.ReceiverCompanyTaxCode,
.ReceiverZipCode = If(i.OtherReceiverZipCode Is Nothing, i.ReceiverZipCode, i.OtherReceiverZipCode),
.IsCreditNote = i.IsCreditNote,
.HasCreditNote = i.HasCreditNote,
.FixedAdditionalAmountOnInvoice = i.FixedAdditionalAmountOnInvoice,
.CashFlowPaymentModeId = If(i.CashFlowPaymentModeId IsNot Nothing, i.CashFlowPaymentModeId.Trim, Nothing),
.AgreementDeductible = i.AgreementDeductible,
.IsPatientInvoiceRecipient = i.IsPatientInvoiceRecipient,
.IsApplicantInvoiceRecipient = i.IsApplicantInvoiceRecipient,
.IsDoctorInvoiceRecipient = i.IsDoctorInvoiceRecipient,
.DoctorId = If(i.DoctorId IsNot Nothing, i.DoctorId, Nothing),
.Doctor = Nothing,
.CreditNoteParentInvoice = i.CreditNoteParentInvoice,
.CreditNoteParentInvoiceYear = i.CreditNoteParentInvoiceYear,
.IsDeferredInvoice = i.IsDeferredInvoice,
.IsExtracted = If(i.IsExtracted IsNot Nothing, i.IsExtracted, False),
.IsExportedToHOST = If(i.IsExportedToHOST IsNot Nothing, i.IsExportedToHOST, False),
.ApplicantId = i.ApplicantId,
.InvoiceHasVAT = i.InvoiceHasVAT,
.VAT_Percentage = i.VAT_Percentage,
.IssuedBy = i.IssuedBy,
.MaskedCounter = i.MaskedCounter,
.DocTypeId = i.DocTypeId,
.OtherReceiverName = i.OtherReceiverName,
.OtherReceiverAddress = i.OtherReceiverAddress,
.OtherReceiverCity = i.OtherReceiverCity,
.OtherReceiverTaxCode = i.OtherReceiverTaxCode,
.OtherReceiverZipCode = i.OtherReceiverZipCode,
.CashFlows = i.CashFlows}).ToList
InvoicesWithDetails is a class that hinerits Invoice; Invoice is a db entity
After this call I loop through the results like this:
For Each i As InvoicesWithDetails In InvoicesQuery.Where(Function(iwd) iwd.CompanyDescription Is Nothing And iwd.CompanyId IsNot Nothing)
i.CompanyDescription = ReturnCompanyDescription(i.CompanyId)
Next
For each cycle in the loop the database is called.
I thought that after the .ToList in the first call I could iterate the results without invoke the database.
What is wrong?
Thanks in advance
Ok, I worked more on that and I tried a different approach:
This is the new query, targeting the Invoice entity:
Dim InvoicesQuery As List(Of Invoice)
InvoicesQuery = (From i As Invoice In dbContext.Invoices.AsNoTracking Where
i.InvoiceDate >= FromDate And i.InvoiceDate <= ToDate).ToList
After that I create a new istance of InvoiceWithDetails and set all the properties like this:
For Each i As Invoice In InvoicesQuery
Dim newInvoiceWithDetails As New InvoicesWithDetails
With newInvoiceWithDetails
.InvoiceDetails = i.InvoicesDetails
.InvoiceDetailsUnmerged = i.InvoicesDetailsUnmergeds
.Examination = Nothing
.Applicant = Nothing
.InvoiceNumber = i.InvoiceNumber
.InvoiceYear = i.InvoiceYear
.DocCode = i.DocCode
.CompanyId = i.CompanyId
.InvoiceDate = i.InvoiceDate
.NetAmount = i.NetAmount
.AmountPaid = i.AmountPaid
.AmountToPay = i.AmountToPay
.VAT = i.VAT
.AdditionalTax = i.AdditionalTax
.Status = i.Status
.Amount = i.Amount
.ExaminationId = i.ExaminationId
.ReceiverName = If(i.OtherReceiverName Is Nothing, i.ReceiverName, i.OtherReceiverName)
.ReceiverAddress = If(i.OtherReceiverAddress Is Nothing, i.ReceiverAddress, i.OtherReceiverAddress)
.ReceiverCity = If(i.OtherReceiverCity Is Nothing, i.ReceiverCity, i.OtherReceiverCity)
.ReceiverTaxCode = If(i.OtherReceiverTaxCode Is Nothing, i.ReceiverTaxCode, i.OtherReceiverTaxCode)
.ReceiverCompanyTaxCode = i.ReceiverCompanyTaxCode
.ReceiverZipCode = If(i.OtherReceiverZipCode Is Nothing, i.ReceiverZipCode, i.OtherReceiverZipCode)
.IsCreditNote = i.IsCreditNote
.HasCreditNote = i.HasCreditNote
.FixedAdditionalAmountOnInvoice = i.FixedAdditionalAmountOnInvoice
.CashFlowPaymentModeId = If(i.CashFlowPaymentModeId IsNot Nothing, i.CashFlowPaymentModeId.Trim, Nothing)
.AgreementDeductible = i.AgreementDeductible
.IsPatientInvoiceRecipient = i.IsPatientInvoiceRecipient
.IsApplicantInvoiceRecipient = i.IsApplicantInvoiceRecipient
.IsDoctorInvoiceRecipient = i.IsDoctorInvoiceRecipient
.DoctorId = If(i.DoctorId IsNot Nothing, i.DoctorId, Nothing)
.Doctor = Nothing
.CreditNoteParentInvoice = i.CreditNoteParentInvoice
.CreditNoteParentInvoiceYear = i.CreditNoteParentInvoiceYear
.IsDeferredInvoice = i.IsDeferredInvoice
.IsExtracted = If(i.IsExtracted IsNot Nothing, i.IsExtracted, False)
.IsExportedToHOST = If(i.IsExportedToHOST IsNot Nothing, i.IsExportedToHOST, False)
.ApplicantId = i.ApplicantId
.InvoiceHasVAT = i.InvoiceHasVAT
.VAT_Percentage = i.VAT_Percentage
.IssuedBy = i.IssuedBy
.MaskedCounter = i.MaskedCounter
.DocTypeId = i.DocTypeId
.OtherReceiverName = i.OtherReceiverName
.OtherReceiverAddress = i.OtherReceiverAddress
.OtherReceiverCity = i.OtherReceiverCity
.OtherReceiverTaxCode = i.OtherReceiverTaxCode
.OtherReceiverZipCode = i.OtherReceiverZipCode
.CashFlows = i.CashFlows
End With
FinalList.Add(newInvoiceWithDetails)
For each cycle and each property value, the database is invoked
Again, what is wrong?