Parse: How to set a pointer in Android?

Question

In my current class, say A, I have a column which is a pointer to another class, say B. Can anyone please let me know how I can set a value for this column in Android?

I have tried fetching the required row from class B as a ParseObject, and doing a:

classAObject.put("column_name",classBParseObject);

But, this is just creating an empty row in my class A, with no pointers. Any help in this regard is much appreciated.

Answer 1

If you have the objectID of the course ID for Computer Science, then you need to save using the createWithoutData method. So let's recap: You have a Student table with a column called CourseId - that is a pointer to the Course table, not the CourseId column of the Course table. You can't point to a column, you point to a table.

So when you create a new Student object, you need to save a pointer into the CourseId column for Computer Science. Let's say the objectID of the Computer Science object in your Course table is "xyz123". You would do the following:

ParseObject student = new ParseObject("Student");
student.put("CourseId", ParseObject.createWithoutData("Course", "xyz123") );
//...set other values for the student object
student.saveInBackground();

The Parse docs has what you need and more - check out the section on relational data: https://parse.com/docs/android_guide#objects-pointers

Answer 2

If it is a custom class then use the following code (Eg : "AnotherClass" is a custom class)

classAObject.put("column_name", ParseObject.createWithoutData("AnotherClass", "abc123"));

or if it is Parse Class like User, Installations etc, use like this,

classAObject.put("column_name", ParseObject.createWithoutData(ParseUser.class, "abc123"));