SQLiteOpenHelper failing to call onCreate?

Question

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)

• So, why is it not calling the onCreate method?
• Or how do i get it to create the database and tables where i am creating the object of the class?
• What would be a better way to do this, if this is not a good approach?

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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      }  } 

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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());    } } 

Answer 1

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

Answer 2

You have to call getWritableDatabase() or getReadableDatabase().