c# – 使用LINQ和Lambda进行多选和连接

发布时间：2020-12-15 08:02:51 所属栏目：百科来源：网络整理

导读：如何使用LINQ和LAMBDA进行此查询？ QUERY Select san_negocio.imovel_id,san_negocio.negocio_id,san_imovel.credenciada_id,san_proposta.proposta_id,san_proposta.credenciada_id from san_negocio join san_proposta on san_negocio.imovel_id = san_pro

如何使用LINQ和LAMBDA进行此查询？

QUERY

Select san_negocio.imovel_id,san_negocio.negocio_id,san_imovel.credenciada_id,san_proposta.proposta_id,san_proposta.credenciada_id
  from san_negocio
  join san_proposta
    on san_negocio.imovel_id = san_proposta.imovel_id
  join san_imovel
    on san_negocio.imovel_id = san_imovel.imovel_id
 where san_negocio.credenciadacaptadora_id is null
   and san_negocio.credenciadavendedora_id is null
   and san_proposta.statusproposta_id = 2

我试过了：

var objetos = db.San_Negocio.Join(db.San_Proposta,a => a.Imovel_Id,b => b.Imovel_Id,(a,b) => new { San_Negocio = a,San_Proposta = b })                
    .Join(db.San_Imovel,a => a.San_Negocio.Imovel_Id,c => c.Imovel_Id,c) => new { San_Negocio = a,San_Imovel = c })
    .Where(a => a.San_Negocio.San_Negocio.CredenciadaCaptadora_Id == null && a.San_Negocio.San_Negocio.CredenciadaVendedora_Id == null)
    .Select(a => new { a.San_Negocio.San_Negocio.Negocio_Id,a.San_Negocio.San_Negocio.Imovel_Id,a.San_Imovel.Credenciada_Id });

我怀疑是在我的选择中.如何调用我的San_Proposta表？

解决方法

这是一个合适的linq声明：

from neg in db.san_negocio
join prop in san_proposta
    on neg.imovel.id equals prop.imovel_id
join imo in san_imovel
    on neg.imovel_id = imo.imovel_id
where neg.credenciadacaptadora_id == null && 
    neg.credenciadavendedora_id == null &&
    prop.statusproposta_id == 2
select new {
    ImovelID = neg.imovel_id,NegocioID = neg.negocio_id,Imo_CredenciadaID = imo.credenciada_id,PropostaID = prop.proposta_id
    Prop_CredenciadaID = prop.credenciada_id
};

这将创建一个具有上面列出的属性的IQueryable匿名对象.

（编辑：李大同）

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