public void LifecycleTest_7_5()
{
LinqBooksDataContext context1 = new LinqBooksDataContext();
LinqBooksDataContext context2 = new LinqBooksDataContext();
context1.Log = Console.Out;
context2.Log = Console.Out;
Guid Id = new Guid("92f10ca6-7970-473d-9a25-1ff6cab8f682");
Subject editingSubject = context1.Subject.Where(s => s.ID == Id).SingleOrDefault();
Console.WriteLine("Before Change:");
ObjectDumper.Write(editingSubject);
ObjectDumper.Write(context2.Subject.Where(s => s.ID == Id));
editingSubject.Description = @"Testing update";
Console.WriteLine("After Change:");
ObjectDumper.Write(context1.Subject.Where(s => s.ID == Id));
ObjectDumper.Write(context2.Subject.Where(s => s.ID == Id));
context1.SubmitChanges();
Console.WriteLine("After Submit Changes:");
ObjectDumper.Write(context1.Subject.Where(s => s.ID == Id));
ObjectDumper.Write(context2.Subject.Where(s => s.ID == Id));
LinqBooksDataContext context3 = new LinqBooksDataContext();
ObjectDumper.Write(context3.Subject.Where(s => s.ID == Id));
//Reset values
editingSubject.Description = "Original Value";
context1.SubmitChanges();
}
public void ConcurrencyDisplayingChanges_8_6()
{
LinqBooksDataContext context = new LinqBooksDataContext();
//Make some changes
this.MakeConcurrentChanges(context);
try
{
context.SubmitChanges(ConflictMode.ContinueOnConflict);
}
catch (ChangeConflictException)
{
var exceptionDetail =
from conflict in context.ChangeConflicts
from member in conflict.MemberConflicts
select new
{
TableName = Helpers.GetTableName(context, conflict.Object),
MemberName = member.Member.Name,
CurrentValue = member.CurrentValue.ToString(),
DatabaseValue = member.DatabaseValue.ToString(),
OriginalValue = member.OriginalValue.ToString()
};
ObjectDumper.Write(exceptionDetail);
}
}
public void ConcurrencyKeepChanges_8_4()
{
LinqBooksDataContext context = this.NewContext;
//Make some changes
this.MakeConcurrentChanges(context);
try
{
context.SubmitChanges(ConflictMode.ContinueOnConflict);
}
catch (ChangeConflictException)
{
context.ChangeConflicts.ResolveAll(RefreshMode.KeepChanges);
//resubmit the merged values
context.SubmitChanges();
}
}
public void UpdateSubject(Subject cachedSubject)
{
LinqBooksDataContext context = new LinqBooksDataContext();
context.Log = Console.Out;
context.Subject.Attach(cachedSubject);
cachedSubject.Name = @"Testing update";
context.SubmitChanges();
}
public void UpdateProcedures_8_16()
{
LinqBooksDataContext context = this.NewContext;
var changingAuthor = context.Author.FirstOrDefault <Author>();
changingAuthor.FirstName = "Changing";
using (System.Transactions.TransactionScope ts = new System.Transactions.TransactionScope())
{
context.SubmitChanges();
//Let the transaction rollback
}
}
public void TransactionsSqlTransactionScope_8_8()
{
LinqBooksDataContext context = this.NewContext;
this.MakeConcurrentChanges(context);
using (System.Transactions.TransactionScope scope =
new System.Transactions.TransactionScope())
{
context.SubmitChanges(ConflictMode.ContinueOnConflict);
scope.Complete();
}
}
public void ConcurrencyOverwriteCurrentValues_8_5()
{
LinqBooksDataContext context = this.NewContext;
//Make some changes
this.MakeConcurrentChanges(context);
try
{
context.SubmitChanges(ConflictMode.ContinueOnConflict);
}
catch (ChangeConflictException)
{
context.ChangeConflicts.ResolveAll(RefreshMode.OverwriteCurrentValues);
}
}
public void TransactionsDataContext_8_8()
{
LinqBooksDataContext context = this.NewContext;
this.MakeConcurrentChanges(context);
try
{
context.Connection.Open();
context.Transaction = context.Connection.BeginTransaction();
context.SubmitChanges(ConflictMode.ContinueOnConflict);
context.Transaction.Commit();
}
catch (ChangeConflictException)
{
context.Transaction.Rollback();
}
}
private void MakeConcurrentChanges(LinqBooksDataContext context)
{
LinqBooksDataContext context1 = this.NewContext;
//First user raises the price of each book
var books1 = context1.Book;
foreach (var book in books1)
{
book.Price += 2;
}
//Second user lowers the price of each book
var books2 = context.Book;
foreach (var book in books2)
{
book.Price -= 1;
}
//Go ahead and submit the first changes.
//The submit using the context passed in to this method will fail.
context1.SubmitChanges();
}