I am trying to create a local database on an android phone using sqlite
.
I have a helper class, shown below, that is used to create the database and provide the "help".
I am wanting to create an object of this class in the main part of my code and it create the database and tables there as well.
The problem:
Whenever i create an object of the class, it does not seem to be calling the onCreate
method in the helper. I thought this is supposed to happen. I thought that onCreate
was basically a constructor for the class. (I believe i am wrong)
onCreate
method? public class SmartDBHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "smart_lite_db.db";
private static final int DATABASE_VERSION = 2;
private static final String NOTIFY_TABLE_NAME = "user_notify_data";
private static final String HR_TABLE_NAME = "user_hr_data";
private static final String NOTIFY_TABLE_CREATE =
"CREATE TABLE " + NOTIFY_TABLE_NAME +
" (counter INTEGER PRIMARY KEY, " +
"userresponse INTEGER, " +
"notifytime INTEGER);";
private static final String DATA_TABLE_CREATE =
"CREATE TABLE " + HR_TABLE_NAME +
" (counter INTEGER PRIMARY KEY, " +
"hr INTEGER, " +
"act INTEGER, " +
"timestamp INTEGER);";
public SmartDBHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
Log.v("smartdbhelper", "before creation");
db.execSQL(NOTIFY_TABLE_CREATE);
Log.v("smartdbhelper", "middle creation");
db.execSQL(DATA_TABLE_CREATE);
Log.v("smartdbhelper", "after creation");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
public class SmartApp extends Activity implements OnSharedPreferenceChangeListener {
private SmartDBHelper dBHelper;
public void onCreate(Bundle savedInstanceState) {
//where i am wanting to create the database and tables
dBHelper = new SmartDBHelper(getContext());
}
}
The onCreate
is not a constructor for the database class. It is only called if you try to open a database that does not exist.
To open/create the database you need to add a call to one of these methods:
public class SmartApp extends Activity implements OnSharedPreferenceChangeListener {
private SmartDBHelper dBHelper;
public void onCreate(Bundle savedInstanceState) {
//where i am wanting to create the database and tables
dBHelper = new SmartDBHelper(getContext());
// open to read and write
dBHelper.getWritableDatabase();
// or to read only
// dBHelper.getReadableDatabase();
}
}
It is a bit big but here is my DatabaseAdapter you can take a look at: http://saintfeintcity.org/projects/sfc/repository/entry/trunk/src/org/saintfeintcity/database/GameDbAdapter.java