c# - LINQ 投影过滤 C#

Question

我想根据包含的表过滤我的 LINQ 查询，但遇到了一些麻烦。

这是原始声明，它有效：

return 
    this.ObjectContext.People.
        Include("Careers").
        Include("Careers.Titles").
        Include("Careers.Titles.Salaries");

现在我正在尝试使用投影过滤来过滤职业，但遇到了麻烦。它编译但它遗漏了 Titles 和 Salaries 表，这会导致运行时错误，我似乎无法将这些表重新添加：

var query1 = (
    from c in 
    this.ObjectContext.People.
        Include("Careers").
        Include("Careers.Titles").
        Include("Careers.Titles.Salaries")
    select new
    {
        c,
        Careers = from Careers in c.Careers
                  where Careers.IsActive == true
                  select Careers
    });

    var query = query1.AsEnumerable().Select(m => m.c);
    return query.AsQueryable();

如何在过滤后的查询中包含职称和薪水表？

Answer 1

您可以大大简化查询，这应该可以解决您的问题。我假设您希望所有人都拥有至少 1 个活跃的职业：

var query = 
    from c in 
    this.ObjectContext.People.
        Include("Careers").
        Include("Careers.Titles").
        Include("Careers.Titles.Salaries")
    where c.Careers.Any(c => c.IsActive);

return query;

Answer 2

我会尝试类似的东西，

var query = from p in ObjectContext.People
            join c in ObjectContext.Careers on p equals c.Person
            where c.IsActive
            select p;