Question

我正在尝试向我的解析数据库添加唯一对象，也就是说，每个对象的name属性必须不同。我尝试查询具有给定名称的所有对象，如此

 var query = new Parse.Query(Food);
 query.exists("name", name);  
 query.count({
 success: function(number) {....}

但是，query.count始终是存储在数据库中的对象总数（90），即使存在具有给定名称的0或1个对象。

编辑：

根据其中一个答案，我将代码修改为此。但是，我仍然在数据库中看到重复项。

var query = new Parse.Query(Food);
query.equalTo("name", name);
query.first({
success: function(results) {...}

以下是整个（编辑过的）功能

Parse.Cloud.define("recordFavorite", function(request, response) {

    var foodList = request.params.foodList; //string array of food names
    var foodListCorrected = new Array();
    var Food = Parse.Object.extend("Food");

    // Wrap your logic in a function
    function process_food(i) {
        // Are we done?
        if (i == foodList.length) {
            //console.log("count is " + foodListCorrected.length);
            Parse.Object.saveAll(foodListCorrected, {
                success: function(foodListCorrected) {},
                error: function(foodListCorrected) {}
            });
            return;
        }

        var name = foodList[i];
        //console.log("before name is " + name);
        var query = new Parse.Query(Food);
        query.equalTo("name", name);

        query.first({
            success: function(results) {
                if(!results){
                    console.log("new");
                    var food = new Food();
                    food.set("name", name);
                    foodListCorrected.push(food);
                    // console.log(foodListCorrected.length);
                } else {
                    //don't create new food
                    console.log("exists");
                }
                process_food(i+1)
            },
            error: function(error) {
                console.log("error");
            }
        });

    }

    // Go! Call the function with the first food.
    process_food(0);

});

编辑：

我已尝试使用promises来解决此问题的另一种方法，但行

return Parse.Object.saveAll(foodListCorrected);

似乎没有执行。我已经验证了foodListCorrected是一个非空数组。下面是该函数的完整代码。

Parse.Cloud.define("recordFavorite", function(request, response) {

  var foodList = request.params.foodList; //string array of food names
  var foodListCorrected = new Array();
  var Food = Parse.Object.extend("Food");

  var query = new Parse.Query(Food);
  query.find().then(function(foods) {
      for (i = 0; i < foodList.length; i++) {
            var j;
            for (j = 0; j < foods.length; j++){
                if (foodList[i] == foods[j])
                  break;
            }
            if (j==foods.length)
                foodListCorrected.push(foodList[i]);
      }
      console.log(foodListCorrected.length);
      return Parse.Object.saveAll(foodListCorrected);
  }).then(function() {
  // Everything is done!

  })

});

Answer 1

试试这个：

Parse.Cloud.define("recordFavorite", function(request, response) { 
    var foodList = request.params.foodList; //string array of food names
    var saveThese = [];

    var FoodClass = Parse.Object.extend("Food");
    for(var i = 0; i < foodList.length; ++i){
        var food = new FoodClass();
        food.set("name", foodList[i]);
        saveThese.push(food);
    }
    Parse.Object.saveAll(saveThese, {
        success: function(list){
            response.success();
        },
        error: function(error){
            response.error("Failure on saving food");
        }
    });
});    

//If a food already exists in the database, then don't save it
Parse.Cloud.beforeSave("Food", function(request, response){
    var query = new Parse.Query("Food");
    query.equalTo("name", request.object.get("name"));
    query.count({
        success: function(count){
            if(count > 0)
                response.error("Food already exists");
            else
                response.success();
        },
        error: function(error){
            response.error(error);
        }
    });
});

Answer 2

＆＃34;存在＆＃34; condition接受一个参数，一个键的名称，并查看它是否存在于行中。因此，它将返回您的＆＃34; name＆＃34; column有一个值，任何值。你正在寻找的是这样的：

 var query = new Parse.Query(Food);
 query.equalTo("name", name);  
 query.first(...)

Parse.com Cloud Code，尝试过滤查询，但查询仍然包含所有对象

2 个答案: