Question

我有一个GroupJoin Query，返回如下结果：

IEnumerable<ICD.ViewModels.HomeSearchViewModel> query = ICDUnitOfWork.AlphaGroups.Find()
    .GroupJoin(ICDUnitOfWork.Alphas.Find(),
        a => a.AlphaGroupID,
        g => g.AlphaGroupID,
        (alphaGroups, alphas) =>
            new ICD.ViewModels.HomeSearchViewModel
            {
                AlphaGroups = alphaGroups,
                Alphas = alphas
            });

Alphas为IEnumerable，AlphaGroup包含多个Alpha。他们都有一个名为“标题”的属性。我需要根据包含字符串“baby”的“Title”属性过滤结果。我怎么能做到这一点？

编辑：我还应该提到，如果某个特定的alpha组标题包含“baby”，则应显示所有具有AlphaGroupID的相应Alpha。

Answer 1

如果您使用的是Entity Framework＆gt; = 4，则Contains将有效：

.Where(row => 
    row.AlphaGroups.Title.Contains("baby") 
        || row.Alphas.Any(alpha => alpha.Title.Contains("baby"))
 );

修改已更新，可预先过滤分组中的字母。最终过滤器排除不包含alphas的行（表示既不 AlphaGroup标题，也不包含任何 Alpha包含字符串）。

IEnumerable<ICD.ViewModels.HomeSearchViewModel> query = ICDUnitOfWork.AlphaGroups.Find()
    .GroupJoin(ICDUnitOfWork.Alphas.Find(),
        a => a.AlphaGroupID,
        g => g.AlphaGroupID,
        (alphaGroups, alphas) =>
            new ICD.ViewModels.HomeSearchViewModel
            {
                AlphaGroups = alphaGroups,
                Alphas = alphas.Where(alpha 
                    => alphaGroups.Title.Contains("baby")
                        || alpha.Title.Contains("baby"))
            });
    .Where(row => row.Alphas.Any());

Answer 2

会推荐.Any()，因为它可以映射到嵌套联盟，而只是过滤预加入

尝试

IEnumerable<ICD.ViewModels.HomeSearchViewModel> query = 
     ICDUnitOfWork.AlphaGroups.Find()
                  .Where(g => g.Title.Contains("baby"))
                  .GroupJoin(ICDUnitOfWork.Alphas.Find()
                                          .Where(a => a.Title.Contains("baby"),
                             a => a.AlphaGroupID,
                             g => g.AlphaGroupID,
                             (alphaGroups, alphas) =>
                                new ICD.ViewModels.HomeSearchViewModel
                                 {
                                  AlphaGroups = alphaGroups,
                                  Alphas = alphas
                                 }).AsEnumerable();

过滤GroupJoin查询

2 个答案: