Android APP crashes on getWritableDatabase() or getReadableDatabase()

Question

I am php developer, trying to learn android and I am trying to set up a DB and insert some data.

I have followed some tutorials but my app gets stuck when I use getWritableDatabase() or getReadableDatabase().

Below is the code for my DBHelper I created.

package com.example.bootstart;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBHelper extends SQLiteOpenHelper {
    private static final String LOGTAG = "THEDBHELPER";

    private static final String DATABASE_NAME = "geolocation.db";
    private static final int DATABASE_VERSION = 1;

    private static final String TABLE_LOCATIONS = "locations";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_welawa = "welawa";
    private static final String COLUMN_lati = "latitude";
    private static final String COLUMN_longi = "longitude";

    private static final String TABLE_CREATE = "CREATE TABLE " + TABLE_LOCATIONS + " ("  
            + COLUMN_ID + "INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_welawa + " TEXT, " + COLUMN_lati 
            + " TEXT, " + COLUMN_longi + " TEXT)"; 


    public DBHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(TABLE_CREATE);
        Log.i(LOGTAG, "TABLE HAS BEEN CREATED");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_LOCATIONS);
        onCreate(db);
    }

}

I access it through my MainActivity class.

package com.example.bootstart;

import android.os.Bundle;
import android.widget.Toast;
import android.app.Activity;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;


public class MainActivity extends Activity {
    SQLiteOpenHelper dbhelper;
    SQLiteDatabase database;
    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toast.makeText(getApplicationContext(), "Main Activity", Toast.LENGTH_LONG).show();

        dbhelper = new DBHelper(this);
            //Works upto here
        database = dbhelper.getReadableDatabase(); //App crashes on this line


    }
}

My emulator crashes on every launch so I am stuck on testing with my phone.

My min SDK is 8, if it is of anyhelp.

Any help is very much appreciated guys.

Answer 1

Simply add a space after 'id' in the

private static final String COLUMN_ID = "id";

I always print my db commands constructed in the code in the log to check as I always make mistakes with the space, brackets or commas. Saves a lot of heartache.

Answer 2

As @Larry suggested, you have a problem in your query. Use this

private static final String TABLE_CREATE = "CREATE TABLE " + TABLE_LOCATIONS + " ("  
            + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + COLUMN_welawa + " TEXT, " + COLUMN_lati 
            + " TEXT, " + COLUMN_longi + " TEXT)"; 

Then I thinks your code will execute. However, I think that you want to create some methods inside your Activity class to get data from database. It is not wrong, but more efficient way will be as follows.

create your methods in DBHelper class and use dbhelper.getReadableDatabase(); there. Eg, If you want to get total records in your table. Add the following code to your DBHelper class.

public int getTotalRecords() {
        SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
        Cursor cursor = sqLiteDatabase.query(TABLE_LOCATIONS, null, null, null, null, null, null, null);
        return cursor.getCount();
    }

Then in MainActivity get the total no. of records like this

dbhelper = new DBHelper(this);
int count = dbhelper.getTotalRecords();