Question

I’ve met an unknown error while inserting data into the database. The LogCat had been display “unable to insert data”, however, the code that I’ve used is copied from another activity (which works).

weird enough, when I placed the code in the onStart() method, it works. but when I placed into my onClick(), it failed.

onStart(): <- not sure whether it’s related to the error

@Override
public void onStart() {
    super.onStart();

    dbopener = new DB_Route_ListOpener(this);

    try {

        dbopener.createDatabase();

    } catch (IOException ioe) {

        throw new Error("Unable to create database");

    }//create database

    try {

        dbopener.openDatabase();

    }catch(SQLException sqle){

        throw sqle;

    }//open database

    // Configure the listview
    routeItems = new ArrayList<String>(dbopener.selectData(new String [] {"RouteName"}, null, null, null, null, null));

    routeListAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,routeItems);
    routeListItem = (ListView)this.findViewById(R.id.mlt_route_list_route);
    routeListItem.setAdapter(routeListAdapter);
    routeListItem.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

    dbopener.close();

}//onStart

onClick():

@Override
public void onClick(View v) {

    // TODO Auto-generated method stub
    if (v == findViewById(R.id.mlt_route_btn_addroute))//add
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setCancelable(false);
        builder.setMessage("Add name ?");

        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() 
        {

            public void onClick(DialogInterface dialog, int which) 
            {
                // TODO Auto-generated method stub
                dialog.dismiss();

                ContentValues cv = new ContentValues();
                cv.put("RouteName", "test");
                dbopener.insertData(null, cv);

            }
        });//clear all data

        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() 
        {

            public void onClick(DialogInterface dialog, int which) 
            {
                // TODO Auto-generated method stub
                dialog.cancel();
            }
        });//negative

        builder.create().show();
    }//if

my insert query:

public void insertData (String nullColumnHack, ContentValues values) {

    try
    {
        myDatabase.insert(DB_TABLE, nullColumnHack, values);
    } catch (Exception e) {
        Log.e("Error :","unable to insert data");
    }//catch

}//insertData

Answer 1

You need to set the dbopener as a global variable and move dbopener.close(); from OnStart() to OnDestroy() since you closed the DB before you insert the data