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Imports System.Data.Linq
Imports System.Transactions
Imports System.Data.Linq.Mapping
Imports System.Reflection
Imports System.Linq
Module Module1
Sub Main()
' <Snippet2>
' Imports System.Reflection
Dim newCust As New Customer()
newCust.City = "Auburn"
newCust.CustomerID = "AUBUR"
newCust.CompanyName = "AubCo"
db.Customers.InsertOnSubmit(newCust)
Try
db.SubmitChanges(ConflictMode.ContinueOnConflict)
Catch e As ChangeConflictException
Console.WriteLine("Optimistic concurrency error.")
Console.WriteLine(e.Message)
Console.ReadLine()
For Each occ In db.ChangeConflicts
Dim metatable As MetaTable = db.Mapping.GetTable(occ.Object.GetType())
Dim entityInConflict = CType(occ.Object, Customer)
Console.WriteLine("Table name: {0}", metatable.TableName)
Console.Write("Customer ID: ")
Console.WriteLine(entityInConflict.CustomerID)
For Each mcc In occ.MemberConflicts
Dim currVal = mcc.CurrentValue
Dim origVal = mcc.OriginalValue
Dim databaseVal = mcc.DatabaseValue
Dim mi = mcc.Member
Console.WriteLine("Member: {0}", mi.Name)
Console.WriteLine("current value: {0}", currVal)
Console.WriteLine("original value: {0}", origVal)
Console.WriteLine("database value: {0}", databaseVal)
Next
Next
Catch ee As Exception
' Catch other exceptions.
Console.WriteLine(ee.Message)
Finally
Console.WriteLine("TryCatch block has finished.")
End Try
' </Snippet2>
End Sub
' <Snippet1>
Dim db As New Northwnd("c:\northwnd.mdf")
' Make changes here.
Sub MakeChanges()
Try
db.SubmitChanges()
Catch e As ChangeConflictException
Console.WriteLine(e.Message)
' Make some adjustments
'...
' Try again.
db.SubmitChanges()
End Try
End Sub
' </Snippet1>
Sub method2()
' this will be s2
End Sub
Sub method3()
' <Snippet3>
Dim db As New Northwnd("c:\northwnd.mdf")
Using ts = New TransactionScope()
Try
Dim prod1 = db.Products.First(Function(p) p.ProductID = 4)
Dim prod2 = db.Products.First(Function(p) p.ProductID = 5)
prod1.UnitsInStock -= 3
prod2.UnitsInStock -= 5
db.SubmitChanges()
ts.Complete()
Catch e As Exception
Console.WriteLine(e.Message)
End Try
End Using
' </Snippet3>
End Sub
' <Snippet6>
Public Sub CreateDatabase()
Dim db As New MyDVDs("c:\...\mydvds.mdf")
db.CreateDatabase()
End Sub
' </Snippet6>
' <Snippet7>
Public Sub CreateDatabase2()
Dim db As MyDVDs = New MyDVDs("c:\...\mydvds.mdf")
If db.DatabaseExists() Then
Console.WriteLine("Deleting old database...")
db.DeleteDatabase()
End If
db.CreateDatabase()
End Sub
' </Snippet7>
End Module
' <Snippet4>
' Code-generating tool defines a partial class, including
' two partial methods.
Partial Class ExampleClass
Partial Private Sub OnFindingMaxOutput()
End Sub
Partial Private Sub OnFindingMinOutput()
End Sub
Sub ExportResults()
OnFindingMaxOutput()
OnFindingMinOutput()
End Sub
End Class
' Developer implements one of the partial methods. Compiler
' discards the other method.
Class ExampleClass
Private Sub OnFindingMaxOutput()
Console.WriteLine("Maximum has been found.")
End Sub
End Class
' </Snippet4>
' <Snippet5>
Public Class MyDVDs
Inherits DataContext
Public DVDs As Table(Of DVD)
Public Sub New(ByVal connection As String)
MyBase.New(connection)
End Sub
End Class
<Table(Name:="DVDTable")> _
Public Class DVD
<Column(IsPrimaryKey:=True)> _
Public Title As String
<Column()> _
Public Rating As String
End Class
' </Snippet5>