使用Entity Framework和LINQ的未知列错误

我昨天开始使用EF，我很难将这个简单的查询转换为EF sintax

翻译：

select a.city from offer o, address a, offer_address oa where o.identifier = oa.offeridentifier and a.identifier = oa.addressidentifier group by a.city order by count(*) desc 

成：

 var cities = (from o in db.offer from a in db.address from oa in db.offer_address where (o.identifier == oa.offeridentifier && a.identifier == oa.addressidentifier) group a by a.city into c select new { quantity = c.Count(), city = c.Key }).OrderByDescending(a => a.quantity).Select(a => a.city); var cityCollection = new List(); foreach (var city in cities) cityCollection.Add(city.ToString()); 

我试过你的成功

 var cities = (from oa in db.offer_address from of in db.offer.Where(x => x.identifier == oa.identifier) from ad in db.address.Where(y => y.identifier == oa.offeridentifier).AsEnumerable() group ad.city by new { ad.city } into g select new { quantity = g.Count(), city = g.Key }).OrderByDescending(a => a.quantity); 

尝试进入第一个循环时会出现问题！

 Unknown column 'GroupBy1.K1' in 'field list'` Line 55: foreach (var city in cities)` 

第二种情况：

Can't group on 'A1'

UPDATE

这段代码有效，但它不是我需要的

 var cities = ( from of in db.offer from ad in db.address from oa in db.offer_address where (of.identifier == oa.offeridentifier && ad.identifier == oa.addressidentifier) group ad.city by new { ad.city } into g select new { quantity = g.Count() }).OrderByDescending(a => a.quantity) 

要么

 var cities = ( from of in db.offer from ad in db.address from oa in db.offer_address where (of.identifier == oa.offeridentifier && ad.identifier == oa.addressidentifier) group ad.city by new { ad.city } into g select new { city = g.Key }); 

Answer 1

更新 – 尝试在第一次选择后添加AsEnumerable()

 var query = (from o in db.offer from a in db.address from oa in db.offer_address where (o.identifier == oa.offeridentifier && a.identifier == oa.addressidentifier) group a by a.city into c select new { quantity = c.Count(), city = c.Key }) .AsEnumerable() .OrderByDescending(a => a.quantity) .Select(a => a.city);