public void SoaTest_7_7()
{
LinqBooksDataContext context1 = new LinqBooksDataContext();
context1.Log = Console.Out;
Guid Id = new Guid("92f10ca6-7970-473d-9a25-1ff6cab8f682");
Subject existingSubject = context1.Subject.Where(s => s.ID == Id).SingleOrDefault();
Console.WriteLine("Starting name: {0}", existingSubject.Name);
Subject changingSubject = new Subject {
ID = existingSubject.ID
};
changingSubject.Name = @"Testing update";
using (System.Transactions.TransactionScope ts = new System.Transactions.TransactionScope())
{
//Apply the changes through a mimiced service
Subject.UpdateSubject(changingSubject);
//Rollback the change after running the demo
}
}
void FillDataSetUsingLinqToSql(LinqBooksDataSet dataSet)
{
var linqBooks = new LinqBooksDataContext(); // 准备LINQtoSQLDataContext
var publisherQuery = from publisher in linqBooks.Publisher
select new { publisher.ID, publisher.Name }; // 查询数据表
var bookQuery = from book in linqBooks.Book
where book.PubDate.Value.Year > 1950
select new
{
book.ID,
book.Title,
book.Subject,
book.Publisher,
Price = book.Price.HasValue ? book.Price.Value : 0
};
foreach (var publisher in publisherQuery)
{
dataSet.Publisher.AddPublisherRow(publisher.ID, publisher.Name, null, null);
}
foreach (var book in bookQuery)
{
dataSet.Book.AddBookRow(book.ID, null, null, 0, book.Price, DateTime.MinValue, dataSet.Publisher.FindByID(book.Publisher), book.Subject, null, book.Title);
}
}
public void DisconnectedTest_7_6()
{
LinqBooksDataContext context1 = new LinqBooksDataContext();
context1.Log = Console.Out;
/* Objects can only be attached to a single context at any given time.
* This is done to avoid the potential to update child objects erroneously.
* For the purposes of this example, we purposefully set up context1 up so that
* it wouldn’t track the changes by setting the ObjectTrackingEnabled to false.
* Attempting to attach an object to a second context will result in a NotSupportedException. */
context1.ObjectTrackingEnabled = false;
Subject cachedSubject = context1.Subject.First();
Console.WriteLine("Starting name: {0}", cachedSubject.Name);
// In a real application, this object would now be cached or remoted via a web service
// Use second context to simulate disconnected environment
using (System.Transactions.TransactionScope ts = new System.Transactions.TransactionScope())
{
UpdateSubject(cachedSubject);
Console.WriteLine("Updated name: {0}", cachedSubject.Name);
//Rollback the change after running the demo
}
}
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 QueryingInheritance_8_28()
{
LinqBooksDataContext context = new LinqBooksDataContext();
context.Log = Console.Out;
//Get all users from the base instance
Console.WriteLine("All users:");
var query =
from user in context.User
select user.Name;
ObjectDumper.Write(query);
Console.WriteLine();
Console.WriteLine("Authors: ");
//Get only the authors
var authors =
from user in context.User
where user is AuthorUser
select user.Name;
ObjectDumper.Write(authors);
Console.WriteLine();
Console.WriteLine("Publishers: ");
//Get the publishers using the OfType extension method
var publishers =
from user in context.User.OfType <PublisherUser>()
select user.Name;
ObjectDumper.Write(publishers);
}
public void UserDefinedScalarFunctions_8_19()
{
LinqBooksDataContext context = this.NewContext;
Guid?PublisherId = new Guid(@"855cb02e-dc29-473d-9f40-6c3405043fa3");
Console.WriteLine(context.fnBookCountForPublisher(PublisherId));
}
public void StoredProcScalar_8_13()
{
Guid publisherId = new Guid("851e3294-145d-4fff-a190-3cab7aa95f76");
LinqBooksDataContext context = this.NewContext;
Console.WriteLine(String.Format("Books found: {0}",
context.BookCountForPublisher(publisherId).ToString()));
}
public void StoredProc_8_11()
{
Guid bookId = new Guid("0737c167-e3d9-4a46-9247-2d0101ab18d1");
LinqBooksDataContext context = this.NewContext;
IEnumerable <Book> query = context.GetBook_Custom(bookId, Thread.CurrentPrincipal.Identity.Name);
ObjectDumper.Write(query);
}
private void EditingForm_Load(object sender, EventArgs e)
{
LinqBooksDataContext context = new LinqBooksDataContext();
var query = from p in context.Publisher
select p;
this.publisherBindingSource.DataSource = query.ToList();
}
public void QueryingPartialClass_8_25()
{
LinqBooksDataContext context = this.NewContext;
var partialAuthors = from author in context.Author
select author;
ObjectDumper.Write(partialAuthors);
}
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 ConcurrencyWithTimestamp_8_3()
{
LinqBooksDataContext context = new LinqBooksDataContext();
var authorToChange = (context.Author).First();
authorToChange.FirstName = "Jim";
authorToChange.LastName = "Wooley";
//Rather than committing a change, just view the SQL that would be used
Console.WriteLine(context.GetChangeText());
}
private void DynamicSql(string searchName)
{
LinqBooksDataContext context = this.NewContext;
string sql = @"Select ID, LastName, FirstName, WebSite, TimeStamp " +
"From dbo.Author " +
"Where LastName = '" + searchName + "'";
IEnumerable <Author> authors = context.ExecuteQuery <Author>(sql);
ObjectDumper.Write(authors);
}
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 DynamicSqlParameters_8_10()
{
string searchName = "Good' OR ''='";
LinqBooksDataContext context = this.NewContext;
string sql =
@"Select ID, LastName, FirstName, WebSite, TimeStamp " +
"From dbo.Author " +
"Where LastName = {0}";
// We should actually have 0 records returned in this case.
ObjectDumper.Write(context.ExecuteQuery <Author>(sql, searchName));
}
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 UserDefinedFunctionsInQuery_8_20()
{
LinqBooksDataContext context = this.NewContext;
var query =
from publisher in context.GetTable <Publisher>()
select new
{
publisher.Name,
BookCount = context.fnBookCountForPublisher(publisher.ID)
};
ObjectDumper.Write(query);
}
public void QueryExpressions_7_3()
{
LinqBooksDataContext context = new LinqBooksDataContext();
var bookParam = Expression.Parameter(typeof(Book), "book");
var query = context.Book.Where <Book>(
Expression.Lambda <Func <Book, bool> >(
Expression.GreaterThan(
Expression.Property(bookParam, typeof(Book).GetProperty("Price")),
Expression.Constant(30M, typeof(decimal?))),
new ParameterExpression[] { bookParam }));
ObjectDumper.Write(query);
}
public void UserDefinedFunctions_8_22()
{
LinqBooksDataContext context = this.NewContext;
Guid publisherId = new Guid("855cb02e-dc29-473d-9f40-6c3405043fa3");
var query1 =
from book in context.fnGetPublishersBooks(publisherId)
select new
{
book.Title,
OtherBookCount = context.fnBookCountForPublisher1(book.Publisher) - 1
};
ObjectDumper.Write(query1);
}
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 DefaultConcurrencyImplementation_8_2()
{
LinqBooksDataContext context = this.NewContext;
var mostExpensiveBook = (from book in context.Book
orderby book.Price descending
select book).First();
decimal discount = .1M;
mostExpensiveBook.Price -= mostExpensiveBook.Price * discount;
//context.SubmitChanges();
//Rather than committing a change, just view the SQL that would be used
Console.WriteLine(context.GetChangeText());
}
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();
}
}
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();
}
}
void FillDataSetUsingLinqToSql(DataSet dataSet)
{
DataTable table;
LinqBooksDataContext linqBooks = new LinqBooksDataContext(); // 准备LINQ to SQL 的DataContext
var publisherQuery =
from publisher in linqBooks.Publisher
select new { publisher.ID, publisher.Name };
var bookQuery = from book in linqBooks.Book
where book.PubDate.Value.Year > 1950
select new
{
book.ID,
book.Title,
book.Subject,
book.Publisher,
Price = book.Price.HasValue ? book.Price.Value : 0
};
table = new DataTable();
table.Columns.Add("ID", typeof(Guid));
table.Columns.Add("Name", typeof(String));
foreach (var publisher in publisherQuery)
{
table.LoadDataRow(new Object[] { publisher.ID, publisher.Name }, true);
}
dataSet.Tables.Add(table);
table = new DataTable();
table.Columns.Add("ID", typeof(Guid));
table.Columns.Add("Title", typeof(String));
table.Columns.Add("Subject", typeof(Guid));
table.Columns.Add("Publisher", typeof(Guid));
table.Columns.Add("Price", typeof(decimal));
foreach (var book in bookQuery)
{
table.LoadDataRow(new Object[] { book.ID, book.Title, book.Subject, book.Publisher, book.Price }, true);
}
dataSet.Tables.Add(table);
}
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();
}
public void CompiledQuery_8_23()
{
ObjectDumper.Write(LinqBooksDataContext.GetExpensiveBooks(30));
}
