Using the right context inside a method to get an sqlite db

Question

I am basically trying to get information from an sqlite db in another class. I've done this without any problems inside the onCreate method, but when I try to use it inside an onClickListener which is inside that onCreate I cannot find the right context to use. My code is as follows:

private AutoCompleteTextView search;
private Button showInfoButton;
private TextView courseInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_courses);
    final Context baseContext = getBaseContext();
    courseInfo = (TextView) this.findViewById(R.id.text);
    DataBase db = new DataBase(this.getApplicationContext());
    db.openDataBase();
    final ArrayList<String> aCourses = db.getCoursesArr();
    db.close();

    search = (AutoCompleteTextView) findViewById(R.id.autocomplete_course);
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_courses, aCourses);
    search.setAdapter(adapter);

    showInfoButton = (Button) this.findViewById(R.id.show_info_button);
    showInfoButton.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            if (aCourses.toString().contains(search.getText()) == false ) {
                courseInfo.setText("Please select a course from the drop-down menu and click on the \"Show course information\" button");
            }
            else{
                String selectedCourse = search.toString();
                DataBase db1 = new DataBase(baseContext);
                db1.openDataBase();
                ArrayList<String> courseAttributes = db1.getCourseAttributes();
                ArrayList<String> attributeValues = db1.getAttributeValues(selectedCourse);
                db1.close();
                String courseInformation = "";
                for (int i=0; i < courseAttributes.size(); i++){
                    courseInformation = courseInformation + courseAttributes.get(i) + ": " + attributeValues.get(i) + System.getProperty("line.separator");
                }
                courseInfo.setText(courseInformation);
            }
        }
    });
}

the problem comes with

DataBase db1 = new DataBase(baseContext);

I've tried changing it to

DataBase db = new DataBase(this.getApplicationContext());

and

DataBase db = new DataBase(null);

and every way I try it, the program does run, but when it get's in the else case it throws an error and shuts down. Could anyone tell me what context should I use in order to make it run?

Answer 1

As you may need the database connection more than once, I recommend to open and close the database connection in your own application class which extends Application.

There you have onCreate and onDestroy methods where you can open and close the database (because it has a context). If you make the database object as a class variable (public static) you should be able to use this like MyApplication.mDatabase.