C# 方法MAX（）从SQL到Linq

嗨，我正在尝试用Linq表达式转换这个SQL脚本

但是我不知道在Linq中如何使用MAX方法

有人能帮我吗

谢谢大家!

SELECT c.Nome, 
       c.NumeroRG, 
       f.Tipo, 
       f.Descricao, 
       f.DataHora,
       f.IdCliente,
       c.IdCliente,
       f.IdFrequencia    
FROM Cliente c, Frequencia f
WHERE f.Tipo = 1
AND   c.IdCliente = f.IdCliente
AND   cast(f.DataHora as date) = cast(getdate() as date)
AND   f.IdFrequencia = (select MAX(fr.IdFrequencia) 
                        from frequencia fr 
                        where fr.IdCliente =c.IdCliente)

---

也许是这样的：

var query = from client in db.Cliente
            join freq in db.Frequencia
            on client.IdCliente equals freq.IdCliente
            where freq.Tipo == 1 
            && freq.DataHora.Date == DateTime.Now.Date
            && freq.IdFrequencia == db.Frequencia.Where(f => f.IdCliente == client.IdCliente)
                                                  Max(f => f.IdFrequencia)
            select new { .... };

---

也许您需要将DateTime.Now.Date/DateTime.Today替换为if-you-use-LINQ-to-Entities，但您没有提到这一点。

这很有效！谢谢

        var query = from client in db.Cliente
                    join freq in db.Frequencia
                    on client.IdCliente equals freq.IdCliente
                    where freq.Tipo == true
                    && freq.DataHora.Value.Date == DateTime.Today.Date
                    && freq.IdFrequencia == db.Frequencia.Where(f => f.IdCliente == client.IdCliente).Max(f => f.IdFrequencia)
                    select new { Nome = client.Nome, Descricao = freq.Descricao };

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db.Frequencia.Maxf=>f.IdCliente==client.IdCliente不能工作，是吗？这如何知道两个Frequencia对象应通过IdFrequencia属性进行比较？我想您需要db.Frequencia.Wheref=>f.IdCliente==client.IdCliente.Maxf=>f.IdFrequenciain&&freq.IdFrequencia==db.Frequencia.Maxf=>f.IdCliente==client.IdCliente我有一个错误消息运算符==不能应用于long和bool类型的opperands=/对不起….:很好！感谢var query=来自db中的客户端。客户端在db中加入freq。客户端上的Frequencia。IDCLIENT等于freq.IDCLIENT，其中freq.Tipo==true和freq.DATAHRA.Value.Date==DateTime.Today.Date和freq.IdFrequencia==db.Frequencia.Wheref=>f.IdCliente==client.IdCliente.Maxf=>f.IdFrequencia选择新的{Nome=client.Nome，descripcao=freq.descripcao}；