Using a compound From clause : From « LINQ « VB.Net






Using a compound From clause

  



Imports System.IO
Imports System.Reflection
Imports System.Linq
Imports System.Xml.Linq
Imports System.Collections
Imports System.Collections.Generic
Public Class Project
    Public ProjectID As Integer
    Public ProjectName As String
    Public Category As String
    Public Cost As Decimal
    Public YearLength As Integer
End Class

Public Class Employee
    Public EmployeeID As String
    Public CompanyName As String
    Public Address As String
    Public City As String
    Public Region As String
    Public PostalCode As String
    Public Country As String
    Public Phone As String
    Public Fax As String
    Public Payments As Payment()
End Class

Public Class Payment
    Public PaymentID As Integer
    Public PaymentDate As DateTime
    Public Total As Decimal
End Class



Public Class MainClass
    Public Shared Sub Main()
        Dim projectList As List(Of Project) = New List(Of Project)
        projectList.Add(New Project With {.ProjectID = 1, .ProjectName = "A", .Category = "Design", .Cost = 18D, .YearLength = 39})
        projectList.Add(New Project With {.ProjectID = 2, .ProjectName = "B", .Category = "Testing", .Cost = 19D, .YearLength = 17})
        projectList.Add(New Project With {.ProjectID = 3, .ProjectName = "C", .Category = "Coding", .Cost = 10D, .YearLength = 13})
        projectList.Add(New Project With {.ProjectID = 4, .ProjectName = "D", .Category = "Meeting", .Cost = 22D, .YearLength = 53})
        projectList.Add(New Project With {.ProjectID = 5, .ProjectName = "E", .Category = "Writing", .Cost = 21.35D, .YearLength = 0})
        projectList.Add(New Project With {.ProjectID = 6, .ProjectName = "F", .Category = "Testing", .Cost = 25D, .YearLength = 120})
        projectList.Add(New Project With {.ProjectID = 7, .ProjectName = "G", .Category = "Coding", .Cost = 30D, .YearLength = 15})
        projectList.Add(New Project With {.ProjectID = 8, .ProjectName = "H", .Category = "Design", .Cost = 40D, .YearLength = 6})
        projectList.Add(New Project With {.ProjectID = 9, .ProjectName = "I", .Category = "Coding", .Cost = 97D, .YearLength = 29})


        Dim employeeList As List(Of Employee) = New List(Of Employee)

        employeeList.Add(New Employee With {.EmployeeID = 1, .CompanyName = "Company A", .Address = "Street 1", .City = "City 1", .Region = "North"})
        employeeList.Add(New Employee With {.EmployeeID = 2, .CompanyName = "Company B", .Address = "Street 2", .City = "City 2", .Region = "South"})
        employeeList.Add(New Employee With {.EmployeeID = 3, .CompanyName = "Company C", .Address = "Street 3", .City = "City 3", .Region = "West"})
        employeeList.Add(New Employee With {.EmployeeID = 4, .CompanyName = "Company D", .Address = "Street 4", .City = "City 4", .Region = "East"})
        employeeList.Add(New Employee With {.EmployeeID = 5, .CompanyName = "Company E", .Address = "Street 5", .City = "City 5", .Region = "North"})
        employeeList.Add(New Employee With {.EmployeeID = 6, .CompanyName = "Company F", .Address = "Street 6", .City = "City 6", .Region = "South"})


        Dim orders = From cust In employeeList, ord In cust.Payments _
                     Where ord.PaymentDate >= #1/1/1998# _
                     Select cust.EmployeeID, ord.PaymentID, ord.PaymentDate

        For Each order In orders
            Console.WriteLine(order.EmployeeID)
        Next

    End Sub


End Class

   
    
  








Related examples in the same category

1.Using compound From clause to select all orders where total is less than 500.00.
2.Compound Select From (select from two arrays)
3.Using a compound From clause to make a query that returns pairs