C# Linq到Sql本地化查询

给定下表，我想返回给定区域性的本地化文本或默认区域性的文本，其中给定区域性不存在行

下面的数据也是如此

资源

ID  Name
1   Donkey
2   Elephant

ID  CultureID  ResID   LocaleText
1   1         1       Donkey
2   1         2       Elephant
3   2         1       baudet

LocaleStrings

ID  Name
1   Donkey
2   Elephant

ID  CultureID  ResID   LocaleText
1   1         1       Donkey
2   1         2       Elephant
3   2         1       baudet

我希望能够为法国文化返回以下内容

baudet
elephant

我尝试了各种基于左连接示例的查询，但我被卡住了

var ct = from r in db.Resources
                 join lt in db.LocaleStrings
                     on r.ID equals lt.ResID into res
                 from x in res.DefaultIfEmpty()
                 select new
                 {
                     CultureID = x.CultureID,
                     LocaleText = x.LocaleText,
                     ResID = x.ResID
                 };

        var text =
            from c in db.Cultures
            join t in ct
            on c.ID equals t.CultureID into cults
            from x in cults.DefaultIfEmpty()
            select x;

---

我相信有更好的方法，但这似乎有效：

    var ct =
        from c in db.Cultures
        from l in db.LocaleStrings
        from r in db.Resources
        where r.ID == l.ResID
        select new
        {
            CultureID = c.ID,
            LocaleText = l.CultureID == c.ID ? l.LocaleText : r.Name,
            ResID = r.ID,
            LSID = l.CultureID == c.ID ? l.ID : 0
        };

    var text =
        from t in ct
        where t.LSID != 0 || (t.LSID == 0 && !((from ac2 in ct
                                                where ac2.LSID > 0 && ac2.CultureID == t.CultureID
                                                select ac2.ResID).Contains(t.ResID)))
        select new
        {
            CultureID = t.CultureID,
            LocaleText = t.LocaleText,
            ResID = t.ResID
        };

---

实际上，您需要进行交叉连接，以将所有文化与所有资源相匹配。这里的左连接将法语与一个资源（baudet）匹配，因此从技术上讲，连接不是空的。