/// <summary>
/// 通过关系获取另一实体类
/// </summary>
/// <typeparam name="TB">要获得的对象</typeparam>
/// <typeparam name="TLink">特殊的关系类</typeparam>
/// <param name="roleA">已知对象</param>
/// <param name="exp">额外条件表达式</param>
/// <returns>所求对象集合</returns>
protected virtual List <TB> GetChildren <TB, TLink>(T roleA, Expression <Func <TB, bool> > exp = null)
where TB : BaseModel, new() where TLink : BaseLink, new()
{
if (!IsExist(roleA))
{
throw new ArgumentException($"{typeof(T).Name}[{roleA.ObjId}]不存在", nameof(roleA));
}
Refresh(ref roleA);
var children = DbClient.Queryable <TLink>().AS("L_" + typeof(T).Name + typeof(TB).Name)
.Where(l => l.RoleAId == roleA.ObjId).ToList();
if (children.IsNullOrEmpty())
{
return(null);
}
var expTemp = new Expressionable <TB>();
foreach (var link in children)
{
expTemp.Or(b => b.ObjId == link.RoleBId);
}
return(DbClient.Queryable <TB>().Where(expTemp.AndIF(exp != null, exp).ToExpression()).ToList());
}
