我使用数据库优先(DB first)的方法。
我有3个带有“Order”列(记录的客户顺序)的表。我想在我的.NET应用程序中创建类似的重新排序逻辑,所以我想使用基类进行操作。我已经创建了以下结构:
但是该项目无法编译,因为每个3个表都没有映射到“Order”列,而且我也找不到一种映射它的方式:
如何表示,“Order”列应该映射到父类的“Order”属性?
更新:
否则,我必须创建类似的方法:
public interface IOrder
{
int Order { get; set; }
}
public partial class EscortDescription : IOrder
{
}
public partial class EscortGroup : IOrder
{
}
public partial class EscortItem : IOrder
{
}
private async Task ReorderEscortAsync(Infrastructure.IOrder item1, Infrastructure.IOrder item2)
{
Random rnd = new Random();
if (item1 == null)
throw new ArgumentNullException("firstItem");
if (item2 == null)
throw new ArgumentNullException("secondItem");
int tmpItem1Order = item1.Order;
int tmpItem2Order = item2.Order;
item1.Order = rnd.Next(int.MinValue, -1);
item2.Order = rnd.Next(int.MinValue, -1);
_db.SaveChanges();
item1.Order = tmpItem2Order;
item2.Order = tmpItem1Order;
await _db.SaveChangesAsync();
}
public async Task EscortGroupItemUpAsync(int ItemID)
{
var firstItem = (from i in _db.EscortItems where i.ID == ItemID select i).FirstOrDefault();
if (firstItem == null)
throw new Domain.RecordNotFoundException<int>(ItemID, "ID", "EscortItems");
var secondItem = (from i in _db.EscortItems where i.Order < firstItem.Order orderby i.Order descending select i).FirstOrDefault();
if (secondItem != null)
await ReorderEscortAsync(firstItem, secondItem);
else
throw new FirstRecordException();
}
public async Task EscortGroupItemDownAsync(int ItemID)
{
var secondItem = (from i in _db.EscortItems where i.ID == ItemID select i).FirstOrDefault();
if (secondItem == null)
throw new Domain.RecordNotFoundException<int>(ItemID, "ID", "EscortItems");
var firstItem = (from i in _db.EscortItems where i.Order > secondItem.Order orderby i.Order ascending select i).FirstOrDefault();
if (firstItem != null)
await ReorderEscortAsync(firstItem, secondItem);
else
throw new LastRecordException();
}
public async Task EscortGroupUpAsync(int ItemID)
{
var firstItem = (from i in _db.EscortGroups where i.ID == ItemID select i).FirstOrDefault();
if (firstItem == null)
throw new Domain.RecordNotFoundException<int>(ItemID, "ID", "EscortGroups");
var secondItem = (from i in _db.EscortGroups where i.Order < firstItem.Order orderby i.Order descending select i).FirstOrDefault();
if (secondItem != null)
await ReorderEscortAsync(firstItem, secondItem);
else
throw new FirstRecordException();
}
public async Task EscortGroupDownAsync(int ItemID)
{
var secondItem = (from i in _db.EscortGroups where i.ID == ItemID select i).FirstOrDefault();
if (secondItem == null)
throw new Domain.RecordNotFoundException<int>(ItemID, "ID", "EscortGroups");
var firstItem = (from i in _db.EscortGroups where i.Order > secondItem.Order orderby i.Order ascending select i).FirstOrDefault();
if (firstItem != null)
await ReorderEscortAsync(firstItem, secondItem);
else
throw new LastRecordException();
}
我希望有一种方法可以传递基类对象作为参数。