LINQ-to-SQL 从变量加载关键字

Question

public IQueryable<ArticleDisplay> SearchNumberOfArticles(int articleNr, string order)
        var result = (
                     from category in db.ArticleCategories
                     join article in db.Articles on category.CategoryID equals article.CategoryID                        
                     orderby article.Date order
                     select new ArticleDisplay
                     {
                         CategoryID = category.CategoryID,
                         CategoryTitle = category.Title,

                         ArticleID = article.ArticleID,
                         ArticleTitle = article.Title,
                         ArticleDate = article.Date,
                         ArticleContent = article.Content
                     }
                     ).Take(articleNr);

在 PHP 中这可以工作，但在 C# 中则不行。那么，如何从变量加载关键字并在查询中“打印”它？这里的 order 假设替换为 descending 或 ascending。 谢谢

Answer 1

您可以使用 if 语句

IQueryable<ArticleDisplay> SearchNumberOfArticles(int articleNr, string order)
{
    ................
    var articles = from category in db.ArticleCategories
                   join article in db.Articles 
                   on category.CategoryID equals article.CategoryID
                   select article;

    if (string.IsNullOrEmpty(order) || order == "ascending" || order = "asc")
    {
        articles = articles.OrderBy(a => a.Date).Take(articleNr);
    }
    else
    {
        articles = articles.OrderByDescending(a => a.Date).Take(articleNr);
    }
    .............
}