/// <summary>
 /// 新增数据
 /// </summary>
 /// <param name="entity"></param>
 /// <param name="saved"></param>
 /// <returns></returns>
 public async Task CreateAsync(TEntity entity, bool saved = true)
 {
     _context.Set <TEntity>().Add(entity);
     if (saved)
     {
         await SaveAsync();
     }
 }