//Insert Province
public static void InsertProvince()
{
var province = new Province {
ProvinceName = "浙江省"
};
province.Donators.Add(new Donator
{
Name = "星空夜焰",
Amount = 50m,
DonateDate = DateTime.Parse("2016-7-12")
});
province.Donators.Add(new Donator
{
Name = "伟涛",
Amount = 30m,
DonateDate = DateTime.Parse("2016-7-12")
});
using (var db = new DonatorsContext())
{
db.Provinces.Add(province);
db.SaveChanges();
}
Console.WriteLine("新建对象，然后添加到数据库上下文，这个表明了EF会追踪当时上下文中为attached或者added状态的实体");
}
//桌面应用,更新Dontor
public static void 桌面应用UpdateDonator()
{
using (var db = new DonatorsContext())
{
var donator = db.Donators.Find(4);
donator.Name = "醉千秋"; //我想把“醉、千秋”中的顿号去掉
db.SaveChanges();
}
Console.WriteLine("桌面应用更新Donators， ");
}
//常规删除数据
public static void 常规删除数据()
{
using (var db = new DonatorsContext())
{
PrintAllDonators(db);
FluentConsole.Green.Line("删除后的数据如下：");
var toDelete = db.Provinces.Find(2);
toDelete.Donators.ToList().ForEach(d => db.Donators.Remove(d));
db.Provinces.Remove(toDelete);
db.SaveChanges();
PrintAllDonators(db);
}
}
//添加捐赠者
public static void AddDonator()
{
using (var context = new DonatorsContext())
{
var donator = new Donator
{
Name = "小黄",
Amount = 12m,
DonateDate = DateTime.MaxValue,
Province = new Province
{
ProvinceName = "新疆"
}
};
context.Donators.Add(donator);
context.SaveChanges();
}
}
public static void Web应用另一种更新操作()
{
var donator = new Donator
{
Id = 5,
Name = "雪茄",
Amount = 12m,
DonateDate = DateTime.Parse("2016-7-13")
};
using (var db = new DonatorsContext())
{
db.Donators.Attach(donator);
//db.Entry(donator).State=EntityState.Modified;//这句可以作为第二种方法替换上面一句代码
donator.Name = "秦皇岛-雪茄";
db.SaveChanges();
}
Console.WriteLine("Web应用另一种更新操作完成！");
}
//Insert Province ,修改实体的状态为added
public static void InsertProvince2()
{
var province = new Province {
ProvinceName = "广东省"
};
province.Donators.Add(new Donator
{
Name = "求余",
Amount = 30,
DonateDate = DateTime.Parse("2016-7-12")
});
using (var db = new DonatorsContext())
{
db.Entry(province).State = EntityState.Added;
db.SaveChanges();
}
Console.WriteLine("InsertProvince,修改实体的状态为added");
}
//设置实体状态删除
public static void 设置实体状态删除()
{
//通过设置实体状态删除
var toDeleteProvince = new Province {
Id = 1
};
toDeleteProvince.Donators.Add(new Donator
{
Id = 2
});
toDeleteProvince.Donators.Add(new Donator
{
Id = 3
});
toDeleteProvince.Donators.Add(new Donator
{
Id = 4
});
using (var db = new DonatorsContext())
{
PrintAllDonators(db); //删除前先输出现有的数据,不能写在下面的using语句中，否则Attach方法会报错，原因我相信你已经可以思考出来了
}
using (var db = new DonatorsContext())
{
db.Provinces.Attach(toDeleteProvince);
foreach (var donator in toDeleteProvince.Donators.ToList())
{
db.Entry(donator).State = EntityState.Deleted;
}
db.Entry(toDeleteProvince).State = EntityState.Deleted; //删除子实体再删除父实体。
db.SaveChanges();
Console.WriteLine("删除之后的数据如下：\r\n");
PrintAllDonators(db);
}
}
//Web应用，更新Province
public static void Web应用UpdateProvince()
{
var province = new Province {
Id = 2, ProvinceName = "山东省更新"
};
province.Donators.Add(new Donator
{
Name = "醉、千秋", //再改回来
Id = 4,
Amount = 12m,
DonateDate = DateTime.Parse("2015-7-12")
});
using (var db = new DonatorsContext())
{
db.Entry(province).State = EntityState.Modified;
foreach (var donator in province.Donators)
{
db.Entry(donator).State = EntityState.Modified;
}
db.SaveChanges();
}
Console.WriteLine("Web应用更新Province");
}