C#/LINQ to SQL - 对来自两个不同结果集的组合结果进行排序

Question

可悲的是，我以前做过这个。我记得弄清楚了。今天，我似乎想不起如何做到这一点。

所以你有这个列表:

public List<taters> getTaters(){
    var firstTaters = from s in n.veggies
                      where s.active == true
                     select s.html;

    var secondTaters = from s in n.roots
                      where s.active == true
                     select s.html;

    //now here I want to do something to combine the two 
    //(e.g. a Concat or some such) and   
    //THEN I want to order the concatenated list of results 
    //by 'date_created' descending.  
}

上述评论中的问题。将它们连接在一起后如何订购？

Answer 1

firstTaters.Concat(secondTaters)
           .OrderByDescending(html => html.date_created)

也尝试在过滤之前对两个集合使用连接，以避免代码重复(可能更慢，但更易于维护)

public IEnumerable<taters> getTaters()
{
    return from s in n.veggies.Concat(n.roots)
           where s.active == true
           orderby s.html.date_created descending
           select s.html;
}

别忘了调用ToList或更改签名以返回 IQueryble<taters>或 IEnumerable<taters>