private void button5_Click(object sender, EventArgs e)
{
WorkRecordDBEntities db = new WorkRecordDBEntities();
#region 1.0 先查后改
//var model = db.UserInfo.Where(m => m.Id == 1003).FirstOrDefault();
//model.UserName = "******";
//model.Email = "*****@*****.**";
#endregion
#region 2.0 自定义一个实体，将要修改的属性重新赋值，将状态修改为Modified
var model = new UserInfo()
{
Id = 1003,
UserName = "******"
};
// 2.0.1 将Model追加到EF容器中，获取代理类对象
System.Data.Entity.Infrastructure.DbEntityEntry dbEntity = db.Entry(model);
dbEntity.State = EntityState.Unchanged;
dbEntity.Property(nameof(UserInfo.UserName)).IsModified = true;
//手动关闭EF对实体验证
db.Configuration.ValidateOnSaveEnabled = false;
#endregion
db.SaveChanges();
MessageBox.Show("数据编辑成功");
}
private void button3_Click(object sender, EventArgs e)
{
WorkRecordDBEntities db = new WorkRecordDBEntities();
UserInfo model;
System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch();
stopwatch.Start();
#region 方法一 1281
for (int i = 0; i < 500; i++)
{
model = new UserInfo()
{
CreateDate = DateTime.Now,
Email = string.Format("lbrunner{0}@163.com", i),
Sex = 1,
UserName = string.Format("lbrunner{0}", i),
};
db.UserInfo.Add(model);
db.SaveChanges();
}
#endregion
#region 方法二 516
//for (int i = 0; i < 500; i++)
//{
// model = new UserInfo()
// {
// CreateDate = DateTime.Now,
// Email = string.Format("lbrunner{0}@163.com", i),
// Sex = 1,
// UserName = string.Format("lbrunner{0}", i),
// };
// db.UserInfo.Add(model);
//}
//db.SaveChanges();
#endregion
stopwatch.Stop();
MessageBox.Show("执行插入500条数据，耗时" + stopwatch.ElapsedMilliseconds.ToString() + "毫秒");
}
private void button2_Click(object sender, EventArgs e)
{
//给UserInfo表中新增一条数据
//1.0 实例化EF上下文容器对象
WorkRecordDBEntities db = new WorkRecordDBEntities();
//2.0 创建一个用户实体
var model = new UserInfo()
{
Email = "*****@*****.**",
Sex = 0,
UserName = "******",
CreateDate = DateTime.Now
};
//3.0 将Model实体追加到EF容器中，同时产生代理类 状态为Added
db.UserInfo.Add(model);
//4.0 通知EF容器，将所有的sql命令发送到数据库
db.SaveChanges();
MessageBox.Show("新增成功");
}
private void button4_Click(object sender, EventArgs e)
{
WorkRecordDBEntities db = new WorkRecordDBEntities();
var model = new UserInfo()
{
Id = 1026
};
#region 1.0 将实体附加到EF容器中，然后调用Remove方法将状态修改为Deleted，最后保存操作
////此时的状态是Unchanged
//db.UserInfo.Attach(model);
////此时的状态是Deleted
//db.UserInfo.Remove(model);
//db.SaveChanges();
#endregion
#region 2.0 将实体附加到EF容器中,然后手动修改状态为Deleted，最后保存
//System.Data.Entity.Infrastructure.DbEntityEntry entityEntry = db.Entry<UserInfo>(model);
//entityEntry.State = EntityState.Deleted;
//db.SaveChanges();
#endregion
#region 3.0 先查后删除
var list = db.UserInfo.Where(u => u.UserName == "lbrunner83");
if (list != null & list.Any())
{
foreach (var item in list)
{
db.UserInfo.Remove(item);
}
}
db.SaveChanges();
#endregion
MessageBox.Show("数据删除成功");
}