Question

您好我正在寻找有关如何将行附加到现有LINQ对象的帮助。在下面的控制器方法中，我有两个结果集，我正在循环站点，并希望为站点对象中的每个记录的“结果”对象添加记录。

我已尝试过concat等但没有到达任何地方，只需要一个小例子来协助，非常感谢提前，J

public IQueryable<UsersToSite> FindAllUsersToSites(int userId,SystemType obj)
{

    var results = (from usersToSite in this._db.UsersToSites
           where usersToSite.UserId == userId &&
           usersToSite.SystemTypeId == obj
           orderby usersToSite.Site.SiteDescription
           select usersToSite);

    // Now for each remaining Site append a record thats not physically in the database. From the view the user will be able to click these records to ADD new
    // I'll then build in a search
    var sites = (from site in this._db.Sites
                 where !(from o in _db.UsersToSites where (o.UserId == userId && o.SystemTypeId == obj) select o.SiteId).Contains(site.SiteId)
           orderby site.SiteDescription
           select site);

    foreach (var site in sites)
    {

        // HERE I want to create the new ROW in results object
        //results = new[results] { new { UsersToSiteId = null, AccessTypeId = null } }.Concat(sites);

            //SiteId=site.SiteId,
            //UsersToSiteId = 0,
            //AccessTypeId = 0,
            //UserId = userId


    }

    return results;
}

Answer 1

我认为你不能，如果你想保持可查询。但是，如果使用ToList（）实现结果，则可以：

var sites = (from site in this._db.Sites
                where !(from o in _db.UsersToSites where (o.UserId == userId && o.SystemTypeId == obj) select o.SiteId).Contains(site.SiteId)
                orderby site.SiteDescription
                select site)
                .ToList();
sites.Add(new Site { UsersToSiteId = null, etc });

如果它是LINQ to Objects，你可以Concat 这里的问题是它无法执行Concat LINQ查询，该查询将包含来自SQL的一部分和来自对象的另一部分。您需要先实现结果，然后连接到对象。

将记录添加到LINQ对象（concat）中，从另一个中获取值

1 个答案: