而不是 FirstOrDefault() 我用什么来获取分组中的所有值？

Question

如何获取 SpecificationDetails_ID 的所有值。通过下面的代码，我只是从一组值中获取第一个值。如何获取所有值？

using(APM context=new APM())
{
      var  lstprodspc = (from s in context.M_ProductSpecifaction
    //join p in context.M_SpecificationDetails on s.SpecificationDetails_ID equals p.ID
    // join r in context.M_Specifications on p.Specification_ID equals r.ID
                          where s.Product_ID == P_ID
                          group s by s.Parent_ID into pg
                          select new 
                          {
                              ProductSD_ID = pg.FirstOrDefault().SpecificationDetails_ID 
                          }).ToList();
}

从上面的代码我只得到 34,31,31,31,26,26,26,26。

Answer 1

您可以像这样使用Select 进行投影：-

 select new 
        {
           Parent_ID = pg.Key,
           ProductSD_ID = pg.Select(x => x.SpecificationDetails_ID).ToList()
        }).ToList();