/// <summary>
/// 基本的 查询 / 插入 / 更新 / 删除 处理.
/// </summary>
private static void BaseTest()
{
TestEntities context = new TestEntities();
// 单表查询
var query =
from testMain in context.test_main
select testMain;
foreach (test_main main in query)
{
Console.WriteLine("Main[{0}, {1}]", main.id, main.value);
}
// 关联查询
var query2 =
from testSub in context.test_sub
where testSub.test_main.value == "ONE"
select testSub;
foreach (test_sub sub in query2)
{
Console.WriteLine("Sub[{0}, {1}]", sub.id, sub.value);
}
// 插入.
test_main main3 = new test_main();
main3.id = 3;
main3.value = "Three";
context.AddObject("test_main", main3);
context.SaveChanges();
Console.WriteLine("INSERT FINISH!");
Console.ReadLine();
// 更新.
var newTestMain =
(from testMain in context.test_main
where testMain.id == 3
select testMain).First();
newTestMain.value = "Three3";
context.SaveChanges();
Console.WriteLine("UPDATE FINISH!");
Console.ReadLine();
// 单表查询 TOP 2
var queryTop2 =
(from testMain in context.test_main
orderby testMain.id descending
select testMain).Take(2);
foreach (test_main main in queryTop2)
{
Console.WriteLine("Main[{0}, {1}]", main.id, main.value);
}
// 删除.
context.DeleteObject(newTestMain);
context.SaveChanges();
Console.WriteLine("DELETE FINISH!");
Console.ReadLine();
}
/// <summary>
/// 事务处理测试.
///
/// 当调用 SaveChanges 时，如果当前事务存在，则对象服务将此事务用于对数据源进行的操作。
/// 否则，将为操作创建新事务。
///
/// 可以使用 EntityTransaction、Transaction 或 TransactionScope 来定义事务。
/// </summary>
private static void TransactionTest()
{
TestEntities context = new TestEntities();
// 插入.
test_main main3 = new test_main();
main3.id = 3;
main3.value = "Three";
context.AddObject("test_main", main3);
// 插入.
test_main main4 = new test_main();
main4.id = 3;
main4.value = "Three 4";
context.AddObject("test_main", main4);
try
{
context.SaveChanges();
}
catch (Exception err)
{
Console.WriteLine(err.ToString());
}
// 单表查询
var query =
from testMain in context.test_main
where testMain.id == 3
select testMain;
Console.WriteLine("TestMain 表中， id=3 的记录有{0}条 ", query.Count());
}
