Complex function using Parse Server Cloud Code (looping and creating records) - parse-server

Question

After a night of trial and error I have decided on a much simpler way to explain my issue. Again, I have no JS experience, so I don't really know what I am doing.
I have 5 classes:
game - holds information about my games
classification - holds information about the user classes available in games
game_classifications - creates a one game to many classifications relationship (makes a game have mulitple classes)
mission - holds my mission information
mission_class - creates a one to many relationship between a mission and the classes available for that mission
Using Cloud Code, I want to provide two inputs through my Rest API being missionObjectId and gameObjectId.
The actual steps I need the code to perform are:
Get the two inputs provided {"missionObjectId":"VALUE","gameObjectId":"VALUE"}
Search the game_classifications class for all records where game = gameObjectID
For each returned record, create a new record in mission_class with the following information:
mission_id = missionObjectId
classification = result.classification
Here is an image of the tables:
And here is how I have tried to achieve this:
Parse.Cloud.define("activateMission", async (request) => {
Parse.Cloud.useMasterKey();
const query = new Parse.query('game_classifications');
query.equalTo("gameObjectId", request.params.gameObjectId);
for (let i = 0; i < query.length; i ++) {
const mission_classification = Parse.Object.extend("mission_class");
const missionClass = new mission_classification();
missionClass.set("mission_id", request.params.missionObjectId);
missionClass.set("classification_id", query[i].classificationObjectId);
return missionClass.save();
}
});
Does anyone have any advice or input that might help me achieve this goal?
The current error I am getting is:
Parse.query is not a constructor
Thank you all in advance!

Answer 1

Some problems on your current code:
Parse.Cloud.useMasterKey() does not exist for quite a long time. Use useMasterKey option instead.
It's Parse.Query and not Parse.query.
You need to run query.findAll() command and iterate over it (and not over query).
For performance, move Parse.Object.extend calls to the beginning of the file.
To access the field of an object, use obj.get('fieldName') and not obj.fieldName.
If you return the save operation, it will save the first object, return, and not save the others.
So, the code needs to be something like this:
const mission_classification = Parse.Object.extend("mission_class");
const game = Parse.Object.extend("game");
Parse.Cloud.define("activateMission", async (request) => {
const query = new Parse.Query('game_classifications');
const gameObj = new game();
gameObj.id = request.params.gameObjectId;
query.equalTo("gameObjectId", gameObj);
const queryResults = await query.findAll({useMasterKey: true});
for (let i = 0; i < queryResults.length; i++) {
const missionClass = new mission_classification();
missionClass.set("mission_id", request.params.missionObjectId);
missionClass.set("classification_id", queryResults[i].get('classificationObjectId'));
await missionClass.save(null, { useMasterKey: true });
}
});