private static void Method09()
{
Member member = new Member { Id = 1, Password = "******" + DateTime.Now.Second };
using (var db = new DataContext())
{
//先查询一次，让上下文中存在相同主键的对象
Member oldMember = db.Members.Single(m => m.Id == 1);
Console.WriteLine("更新前：{0}。", oldMember.AddDate);
db.Update<Member>(m => new { m.Password }, member);
int count = db.SaveChanges(false);
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db.Members.Single(m => m.Id == 1);
Console.WriteLine("更新后：{0}。", newMember.Password);
}
}
//情景一：取出数据更新后直接保存
private static void Method01()
{
using (var db = new DataContext())
{
const string userName = "******";
Member oldMember = db.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新前：{0}。", oldMember.AddDate);
oldMember.AddDate = oldMember.AddDate.AddMinutes(10);
db.Update(oldMember);
int count = db.SaveChanges();
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新后：{0}。", newMember.AddDate);
}
}
private static void Method08()
{
Member member = new Member { Id = 1, Password = "******" + DateTime.Now.Second };
using (var db = new DataContext())
{
//先查询一次，让上下文中存在相同主键的对象
Member oldMember = db.Members.Single(m => m.Id == 1);
Console.WriteLine("更新前：{0}。", oldMember.AddDate);
try
{
DbEntityEntry<Member> entry = db.Entry(member);
entry.State = EntityState.Unchanged;
entry.Property("Password").IsModified = true;
}
catch (InvalidOperationException)
{
ObjectContext objectContext = ((IObjectContextAdapter)db).ObjectContext;
ObjectStateEntry objectEntry = objectContext.ObjectStateManager.GetObjectStateEntry(oldMember);
objectEntry.ApplyCurrentValues(member);
objectEntry.ChangeState(EntityState.Unchanged);
objectEntry.SetModifiedProperty("Password");
}
db.Configuration.ValidateOnSaveEnabled = false;
int count = db.SaveChanges();
db.Configuration.ValidateOnSaveEnabled = true;
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db.Members.Single(m => m.Id == 1);
Console.WriteLine("更新后：{0}。", newMember.Password);
}
}
private static void Method06()
{
Member member = new Member { Id = 1, Password = "******" + DateTime.Now.Second };
using (var db = new DataContext())
{
DbEntityEntry<Member> entry = db.Entry(member);
entry.State = EntityState.Unchanged;
entry.Property("Password").IsModified = true;
db.Configuration.ValidateOnSaveEnabled = false;
int count = db.SaveChanges();
db.Configuration.ValidateOnSaveEnabled = true;
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db.Members.Single(m => m.Id == 1);
Console.WriteLine("更新后：{0}。", newMember.Password);
}
}
private static void Method05()
{
const string userName = "******";
Member updateMember;
using (var db1 = new DataContext())
{
updateMember = db1.Members.Single(m => m.UserName == userName);
}
updateMember.AddDate = DateTime.Now;
using (var db2 = new DataContext())
{
//先查询一次，让上下文中存在相同主键的对象
Member oldMember = db2.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新前：{0}。", oldMember.AddDate);
db2.Update<Member>(updateMember);
int count = db2.SaveChanges();
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db2.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新后：{0}。", newMember.AddDate);
}
}
static void Main(string[] args)
{
try
{
var migrate = new MigrateDatabaseToLatestVersion<DataContext, Configuration>();
Database.SetInitializer(migrate);
using (var db = new DataContext())
{
Console.WriteLine("数据初始化完成：部门信息{0}条，角色信息{1}条，人员信息{2}条", db.Departments.Count(), db.Roles.Count(), db.Members.Count());
}
}
catch (Exception e)
{
Console.WriteLine(new ExceptionMessage(e));
}
Reinput:
try
{
Console.WriteLine("请输入：功能1-n，退出0");
int input;
if (!int.TryParse(Console.ReadLine(), out input))
{
goto Reinput;
}
switch (input)
{
case 0:
break;
case 1:
Method01();
goto Reinput;
case 2:
Method02();
goto Reinput;
case 3:
Method03();
goto Reinput;
case 4:
Method04();
goto Reinput;
case 5:
Method05();
goto Reinput;
case 6:
Method06();
goto Reinput;
case 7:
Method07();
goto Reinput;
case 8:
Method08();
goto Reinput;
case 9:
Method09();
goto Reinput;
default:
Console.WriteLine("编号{0}的功能不存在。\r\n", input);
goto Reinput;
}
}
catch (Exception e)
{
Console.WriteLine(new ExceptionMessage(e));
goto Reinput;
}
}
//情景三：在情景二的基础上，上下文2中已存在与外来实体主键相同的数据了，引发InvalidOperationException异常
private static void Method03()
{
const string userName = "******";
Member updateMember;
using (var db1 = new DataContext())
{
updateMember = db1.Members.Single(m => m.UserName == userName);
}
updateMember.AddDate = DateTime.Now;
using (var db2 = new DataContext())
{
//先查询一次，让上下文中存在相同主键的对象
Member oldMember = db2.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新前：{0}。", oldMember.AddDate);
var dbset = db2.Members.Local;
db2.Members.Attach(updateMember);
DbEntityEntry<Member> entry = db2.Entry(updateMember);
Console.WriteLine("Attach成功后的状态：{0}", entry.State); //附加成功之后，状态为EntityState.Unchanged
entry.State = EntityState.Modified;
int count = db2.SaveChanges();
Console.WriteLine("操作结果：{0}", count > 0 ? "更新成功。" : "未更新。");
Member newMember = db2.Members.Single(m => m.UserName == userName);
Console.WriteLine("更新后：{0}。", newMember.AddDate);
}
}