Issue in accessing database in Android, Table isn't getting created

Question

It seems like the database gets created, but I get error when I try to access the database that was created. Whenever the doQuery() is invoked, the app crashes. Could you please help me figure out what I am doing wrong?

private class LoadCursorTask extends AsyncTask<Void, Void, Void>
   {
        Cursor constantCursor=null;     

    @Override       
    protected Void doInBackground(Void... params)
    {

        // TODO Auto-generated method stub
        Log.d("Action1","in doInBacground()"); 
        constantCursor=doQuery(); 
        Log.d("Action1","after doQuery ");
        constantCursor.getCount(); 

        return null;
    }


}


private Cursor doQuery() 
{

    Log.d("Action1","in doQuery()");
    Cursor localCursor= db.getReadableDatabase().rawQuery("SELECT _id,  title, value"+" FROM constants ORDER BY title; ", null);
    Log.d("Action1","before returning from doQuery()"); 
    return localCursor; 
}

The error report on stacktrack show like this:

08-02 11:23:31.012: E/SQLiteLog(1829): (1) no such table: constants
08-02 11:23:31.040: W/dalvikvm(1829): threadid=11: thread exiting with uncaught exception (group=0x40a71930)
08-02 11:23:31.173: E/AndroidRuntime(1829): FATAL EXCEPTION: AsyncTask #1
08-02 11:23:31.173: E/AndroidRuntime(1829): java.lang.RuntimeException: An error occured while executing doInBackground()
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.os.AsyncTask$3.done(AsyncTask.java:299)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.FutureTask.run(FutureTask.java:239)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.lang.Thread.run(Thread.java:856)
08-02 11:23:31.173: E/AndroidRuntime(1829): Caused by: android.database.sqlite.SQLiteException: no such table: constants (code 1): , while compiling: SELECT _id,  title, value FROM constants ORDER BY title;
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at com.example.database_constants.ConstantsFragment.doQuery(ConstantsFragment.java:28)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at com.example.database_constants.ConstantsFragment.access$0(ConstantsFragment.java:25)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at com.example.database_constants.ConstantsFragment$LoadCursorTask.doInBackground(ConstantsFragment.java:47)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at com.example.database_constants.ConstantsFragment$LoadCursorTask.doInBackground(ConstantsFragment.java:1)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at android.os.AsyncTask$2.call(AsyncTask.java:287)
08-02 11:23:31.173: E/AndroidRuntime(1829):     at java.util.concurrent.FutureTask.run(FutureTask.java:234)
08-02 11:23:31.173: E/AndroidRuntime(1829):     ... 4 more

Here's how I've created the database:

db.execSQL("CREATE TABLE constants (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, value REAL);");

[UPDATE 1] Here's the DatabaseHelper.class

public class DatabaseHelper extends SQLiteOpenHelper
{
    private static final String DATABASE_NAME="constants.db";
  private static final int SCHEMA=1; 
  static final String TITLE="title"; 
  static final String VALUE="value"; 
  static final String TABLE="constants";


public DatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, SCHEMA);
    // TODO Auto-generated constructor stub
    Log.d("Action1","in DatabaseHelper constructor"); 
}

@Override
public void onCreate(SQLiteDatabase db)
{
    Log.d("Action1","in onCreate");
    try
    {
        db.beginTransaction();
        db.execSQL("CREATE TABLE constants (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, value REAL)");

        ContentValues cv=new ContentValues(); 

        cv.put(TITLE, "Gravity, Death Star I"); 
        cv.put(VALUE, SensorManager.GRAVITY_DEATH_STAR_I); 
        db.insert("constants", TITLE, cv);

        cv.put(TITLE, "Gravity, Earth"); 
        cv.put(VALUE, SensorManager.GRAVITY_EARTH); 
        db.insert("constants", TITLE, cv); 

        cv.put(TITLE, "Gravity, Jupiter"); 
        cv.put(VALUE, SensorManager.GRAVITY_JUPITER); 
            db.insert("constants", TITLE, cv); 
    }
        finally
    {

        db.endTransaction(); 
    }

}
}

Answer 1

It's probably not finding your database file, and creating a new empty one when you try to open it. Check the name and location of your database. If you're creating it in code, make sure to create the table before you try to access it.

EDIT:

Found your issue, you need to mark the transaction as successfull before the endTransaction, else it gets rolled back.

@Override
public void onCreate(SQLiteDatabase db)
{
    Log.d("Action1","in onCreate");
    try
    {
        db.beginTransaction();
        db.execSQL("CREATE TABLE constants (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, value REAL)");

        ContentValues cv=new ContentValues(); 

        cv.put(TITLE, "Gravity, Death Star I"); 
        cv.put(VALUE, SensorManager.GRAVITY_DEATH_STAR_I); 
        db.insert("constants", TITLE, cv);

        cv.put(TITLE, "Gravity, Earth"); 
        cv.put(VALUE, SensorManager.GRAVITY_EARTH); 
        db.insert("constants", TITLE, cv); 

        cv.put(TITLE, "Gravity, Jupiter"); 
        cv.put(VALUE, SensorManager.GRAVITY_JUPITER); 
        db.insert("constants", TITLE, cv);
        db.setTransactionSuccessful();
    }
        finally
    {

        db.endTransaction(); 
    }

}

Source