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Master-detail relation in LINQ to SQL for Windows Phone 7.1
using System;
using System.ComponentModel;
using System.Data.Linq;
using System.Data.Linq.Mapping;
using System.Linq;
using Microsoft.Silverlight.Testing;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace blah
{
public class TestDb : DataContext
{
public TestDb(string connectionString) : base(connectionString)
{ }
public Table<Master> Masters;
public Table<Detail> Details;
}
[Table]
public class Master
{
private int _id;
[Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
public int Id
{
get { return _id; }
set { _id = value; }
}
private string _title;
[Column(CanBeNull = false)]
public string Title
{
get { return _title; }
set { _title = value; }
}
private EntitySet<Detail> _details;
[Association(Storage = "_details", OtherKey = "_masterId", ThisKey = "Id", DeleteRule = "CASCADE")]
public EntitySet<Detail> Details
{
get { return _details; }
set { _details.Assign(value); }
}
public Master()
{
_details = new EntitySet<Detail>(
detail => detail.Master = this,
detail => detail.Master = null);
}
}
[Table]
public class Detail
{
private int _id;
[Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
public int Id
{
get { return _id; }
set { _id = value; }
}
private string _title;
[Column(CanBeNull = false)]
public string Title
{
get { return _title; }
set { _title = value; }
}
[Column(CanBeNull = false)]
internal int _masterId;
private EntityRef<Master> _master;
[Association(Storage = "_master", ThisKey = "_masterId", OtherKey = "Id", IsForeignKey = true, DeleteOnNull = true)]
public Master Master
{
get { return _master.Entity; }
set
{
Master previousValue = _master.Entity;
if ((previousValue != value) || (_master.HasLoadedOrAssignedValue == false))
{
if (previousValue != null)
{
_master.Entity = null;
previousValue.Details.Remove(this);
}
_master.Entity = value;
if (value != null)
{
value.Details.Add(this);
_masterId = value.Id;
}
}
}
}
}
[TestClass]
public class UnitTests : SilverlightTest
{
private readonly String KDBConnectionString = "Data Source=isostore:/testdb.sdf";
[TestMethod]
[Microsoft.VisualStudio.TestTools.UnitTesting.Description("TestDb")]
public void TestDb()
{
using (TestDb db = new TestDb(KDBConnectionString))
{
if (db.DatabaseExists())
{
db.DeleteDatabase();
}
db.CreateDatabase();
Assert.IsTrue(db.DatabaseExists(), "Setup failed");
db.Masters.InsertOnSubmit(new Master() { Title = "M" });
db.SubmitChanges();
Assert.IsTrue(db.Masters.Count() == 1, "No master created");
db.Details.InsertOnSubmit(new Detail() { Title = "D1", Master = db.Masters.First() });
db.SubmitChanges();
Assert.IsTrue(db.Details.Count() == 1, "No details created");
Assert.IsTrue(db.Masters.First().Details.Count() == 1, "No detail in master");
Assert.IsTrue(db.Masters.First() == db.Details.First().Master, "Master mismatch");
db.Masters.First().Details.Add(new Detail() { Title = "D2" });
db.SubmitChanges();
Assert.IsTrue(db.Details.Count() == 2, "2nd detail not created");
Assert.IsTrue(db.Masters.First().Details.Count() == 2, "2nd detail not added to master");
db.Masters.DeleteOnSubmit(db.Masters.First());
db.SubmitChanges();
Assert.IsTrue(db.Masters.Count() == 0, "Master delete failed");
Assert.IsTrue(db.Details.Count() == 0, "Cascaded detail delete failed");
db.DeleteDatabase();
Assert.IsFalse(db.DatabaseExists(), "Cleanup failed");
}
}
}
}
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