相关疑难解决方法(0)

我正在尝试通过if语句调整我的查询,如下所示:

        IQueryable articles = null;

        if (User.IsInRole("Admin"))
        {
            articles = from s in db.Articles
                       select s;
        }
        if (User.IsInRole("Educator"))
        {
            articles = from s in db.Articles
                       where s.createdBy == WebSecurity.CurrentUserName
                       select s;

        }

这似乎没有给我任何错误.但是,当我尝试使用where子句进行更多过滤时,它无法识别该术语.我理解IQuerable不支持它,但有没有办法将"articles"设置为null,然后用if语句设置它？

if (!String.IsNullOrEmpty(searchString))
        {
            articles = articles.Where(s => s.title.ToUpper().Contains(searchString.ToUpper())
                                   || s.content.ToUpper().Contains(searchString.ToUpper()));
        }
        switch (sortOrder)
        {
            case "name_desc":
                articles = articles.OrderByDescending(s => s.title);
                break;
            case "Date":
                articles = articles.OrderBy(s => s.dateCreated);
                break;
            case "date_desc":
                articles = articles.OrderByDescending(s => s.dateCreated);
                break;
            case "rating_desc":
                articles = articles.OrderByDescending(s => s.finalReview);
                break; …