CODEWITHSUNDEEP
androidsqlite
Josh
Josh

Reputation: 2725

Android: Unable to open database file halfway through functioning loop

I have a function that adds up numbers from a SQLLite database and then writes a total in that same database. I am doing this in a background task while the main activity waits.

This works properly for some time, but fails with the below, usually about halfway through the loop:

Unable to open database file (code 14):, while compiling: PRAGMA journal_mode

This happens at a different line in the database each time, so I don't think its one entry causing the error.

My code---

Activity:

...
calculateStats();
...


public void  calculateStats(final String MY_GROUP){



   calculateTask = new AsyncTask<Void, Void, Void>() {

            @Override
               protected Void doInBackground(Void... params) {
                Looper.prepare();
                StatCalculator calculator = new StatCalculator();
                calculator.writeTotalA(MY_GROUP);
                calculator.writeTotalB(MY_GROUP);
                calculator = null;

                   return null;
               }

               @Override
               protected void onPostExecute(Void result) {



                }
           };
           calculateTask.execute(null, null, null);

 }

StatCalculator:

public void writeTotalB(String my_group){
    DatabaseManager db = new DatabaseManager(this); 
    DB_GROUP = "DB" + my_group+ ".DB";

    SQLiteDatabase groupDB = SQLiteDatabase.openDatabase(DB_PATH + DB_GROUP, null, SQLiteDatabase.OPEN_READWRITE); 
     Cursor groupCursor = groupDB .query("ItemTable", null, null, null, null, null, null);



     if (groupCursor != null  ) {
          for (int i = 0; i < groupCursor .getCount(); i++) {


            ...
            //calculating total here (totalPoints)
            ...     



     //write total to database:
    db.update_byID(DB_GROUP , id, "Total", totalPoints);



          }


      }

     groupDB .close();
     groupCursor.close();
      db = null;
}

The code makes it entirely through calculator.writeTotalA(MY_GROUP) successfully. The crash always takes place halfway through calculator.writeTotalB(MY_GROUP)

I am not sure if this is because I am reading and writing to this database at the same time or what. I would think it would crash sooner if that was the case.

Any help would be greatly appreciated.

Upvotes: 1

Views: 2217

Answers (1)

Josh
Josh

Reputation: 2725

Got it.

The method

db.update_byID(DB_GROUP , id, "Total", totalPoints);

was opening a new instance of the database for each entry and then not closing it.

Upvotes: 2

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