Question

嗨，我在实体框架中有查询，但是它不起作用。你有什么想法吗？

我需要这个结果

SELECT id, min(price) minPrice
    FROM (
        SELECT id, max(servicePrice) msi FROM offers
            GROUP BY id
        ) as mvo INNER JOIN offers so ON mvo.id=so.id AND mvo.msi=so.servicePrice
    WHERE so.id=o.id
    GROUP BY so.id

我尝试了以下代码，但是有两个错误。 Join返回The type of one of the expressions in the join clause is incorrect. Type inference failed in the call to 'Join'.。没有minPrice = ms.Min(s => s.price)时，最后一次选择可以正常工作。当我有min函数时，运行时将返回System.ArgumentException: 'Value does not fall within the expected range.'

var q = 
    from vo in dataContext.Offers join so in (
        from o in dataContext.Offers
            group o by o.id into oo
            select new { id = oo.Key, MaxSI = oo.Max(v => (v.servicePrice)) }
    ) on new { vo.id, vo.servicePrice } equals new { so.id, so.MaxSI }
        group vo by vo.id into ms
        select new { id = ms.Key, minPrice = ms.Min(s => s.price) }
    ;

Answer 1

我认为加入应该像这样-

var q = 
    from vo in dataContext.Offers join so in (
        from o in dataContext.Offers
            group o by o.id into oo
            select new { id = oo.Key, MaxSI = oo.Max(v => (v.servicePrice)) }
    ) 
    on new { id = vo.id, price = vo.servicePrice } equals new { id = so.id, price = so.MaxSI }
    group vo by vo.id into ms
    select new { id = ms.Key, minPrice = ms.Min(s => s.price) }
 ;

带有联接的EF查询未运行

1 个答案: