public void Add(DeviceTypeModel instance)
{
using (var db = new TestHXContext())
{
db.DeviceType.Add(instance);
db.SaveChanges();
}
}
public void Delete(DeviceModel instance)
{
using (var db = new TestHXContext())
{
db.Entry <DeviceModel>(instance).State = System.Data.Entity.EntityState.Deleted;
db.SaveChanges();
}
}
public void Delete(DeviceTypeModel instance)
{
using (var db = new TestHXContext())
{
DeviceTypeModel dtm = db.DeviceType.Find(instance.Id);
db.Entry <DeviceTypeModel>(dtm).State = System.Data.Entity.EntityState.Deleted;
//获取关联的设备并更新外键为Null
var d = db.Device.Where(a => a.TypeId == instance.Id);
foreach (var item in d)
{
item.TypeId = null;
}
db.SaveChanges();
}
}