.net - LINQ - 动态 orderby 子句不起作用

Question

我有这样的代码:

//build query
var shops = (from p in dataContext.shops
let distance = dataContext.GetDistance(p.lat, p.lon, nearlat,nearlon)
                     join c in dataContext.shops_category on p.id equals c.poi_id
                     select new ShopsModel { p = p, distance = distance }
                         );
        }
//add dynamic orderby
if(somthig) 
  shops.OrderBy(distance)
else 
  shops.OrderBy(p.name)


//get records.
return shop.Take(30).ToList()

除了 OrderBy 之外，它工作正常。生成的 SQL 代码不包含 orderby 子句，并且记录未排序。

任何的想法？感谢帮助。

Answer 1

OrderBy 不会改变底层数据——它返回一个具有适当排序的枚举。您需要将结果分配回商店:

if (someCondition) 
{
  shops = shops.OrderBy(shop => shop.distance);
}
else 
{
  shops = shops.OrderBy(shop => shop.p.name);
}