在 Xamarin.Android 上从 Parse.com 检索具有许多关系的查询

Question

我试图弄清楚如何做到这一点。在documentation 上，它有一个关于如何获取具有一个关系的查询的示例：

// suppose we have a book object
var book = ...

// create a relation based on the authors key
var relation = book.GetRelation<ParseObject>("authors");

// generate a query based on that relation
var query = relation.Query;

// now execute the query
query.FindAsync ();

但如果我有 3 种关系，就像我的情况一样？

reviewObject =  new ParseObject("Review");
var relationBusiness = reviewObject.GetRelation<ParseObject>("business");
relationBusiness.Add(application.currentBusiness);
var relationUser = reviewObject.GetRelation<ParseObject>("user");
relationUser.Add(ParseUser.CurrentUser);
var relationStaff = reviewObject.GetRelation<ParseObject> ("staff");
relationStaff.Add (application.currentStaff);

请帮忙。谢谢

Answer 1

毕竟没那么难：

var query = ParseObject.GetQuery ("Review")
    .WhereEqualTo ("business", relationBusiness)
    .WhereEqualTo ("user", relationUser)
    .WhereEqualTo ("staff", relationStaff);

IEnumerable<ParseObject> reviews = await query.FindAsync();

（relationBusiness、relationUser 和 relationStaff 是 ParseObject 而不是关系）