static void Main(string[] args)
{
CodeFirstDbContext db = new CodeFirstDbContext();
db.Database.CreateIfNotExists();
ClassInfo classInfo = new ClassInfo();
classInfo.ClassName = "0413班";
classInfo.CreateTime = DateTime.Now;
db.ClassInfo.Add(classInfo);
db.SaveChanges();
}
static void Main(string[] args)
{
CodeFirstDbContext dbContext = new CodeFirstDbContext();
dbContext.Database.CreateIfNotExists();
#region 增加
/*
* UserInfo user = new UserInfo();
* user.SName = "shaocx";
*
* dbContext.UserInfo.Add(user);//告诉EF咱们对上面的实体做一个插入操作
* dbContext.SaveChanges();//告诉上下文把实体的变化保存到数据库中
* //*/
#endregion
#region 修改
/*
* UserInfo modified = new UserInfo();
* modified.SName = "我是猪";
* modified.ID = 1;
*
* dbContext.Entry<UserInfo>(modified).State = System.Data.Entity.EntityState.Modified;
* //单独指定要修改的列
* //dbContext.Entry<UserInfo>(modified).Property<string>(u => u.SName).IsModified = true;
*
* dbContext.SaveChanges();
*
* //*/
#endregion
#region 除
/*
*
* UserInfo del = new UserInfo();
* del.ID = 1;
*
* dbContext.Entry<UserInfo>(del).State = System.Data.Entity.EntityState.Deleted;
*
* dbContext.SaveChanges();
*
* //*/
#endregion
#region 查询
var temp = from u in dbContext.UserInfo
where u.ID > 0
//where u.ID>0 && u.SName.Contains("shaocx") && u.SName.StartsWith("S")
select u;
foreach (var userInfo in temp)
{
Console.WriteLine(userInfo.ID + " " + userInfo.SName);
}
//两种延迟加载
#region 1、第一种延迟加载 用到的时候才去加载
var temp2 = from u in temp
where u.ID > 0
select u;
foreach (var userInfo in temp2)
{
Console.WriteLine(userInfo.ID + " " + userInfo.SName);
}
#endregion
#region 2、第二种延迟加载，
foreach (var userInfo in temp)
{
//如果userInfo.OrderInfo为Null的情况，则EF会每次循环前加载OrderInfo数据
foreach (var order in userInfo.OrderInfo)
{
Console.WriteLine(order.id + " " + order.name);
}
}
#endregion
#endregion
Console.WriteLine("ok....");
Console.ReadKey();
}
