SQLite exception: Database is locked issue

Question

I'm having an issue with my SQLite database inside an Android app. It seems to happen every so often and I cannot reproduce it, but this is the report the Android Market gives. Basically I have first a splash screen activity that starts by checking if all the needed data is in the database. If not, it will install the data in a asynchronous thread and close the db connection. Then and only then can the main activity be started, which also opens and reads/writes the database. This code is executed from the onCreate method of the splash screen activity: ``` dbWord = new WordDBAdapter(this, myUI); dbWord.open(); if (dbWord.isDataInstalled()) { dbWord.close(); databaseInstalled = true; clickToStartView.setText(myUI.PRESS_TO_START); clickToStartView.startAnimation(myBlinkAnim); } else { // If not, try to install in asynchronous thread progressDialog = new ProgressDialog(this); progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); progressDialog.setMessage(myUI.INSTALLING_DB); p…

Accepted Answer

After doing some effort I did it (My app was working on perfect till android 2.3 but got db lock error when I used to run it on HoneyComb tablet). I did using Semaphores (using lock in critical sections).

Example 1

```
public class DbExp extends SQLiteOpenHelper{
    public static String Lock = "dblock";
    private static final String DATABASE_NAME = "db.db";
    private static final String TABLE_NAME = "table_name";

public void delete(Context mContext){
        synchronized(Lock) {
            SQLiteDatabase db  = getWritableDatabase();
            db.delete(TABLE_NAME, null, null);
            db.close();
        }
    }

public void insert(){
        synchronized(Lock) {
            SQLiteDatabase db  = getWritableDatabase();
            db.insert(TABLE_NAME, ..., ...);
            db.close();
        }
    }

}
```

Example 2

```
public class DB {
    public static String Lock = "dblock";
    private static final String DATABASE_NAME = "db.db";
    private static final String TABLE_NAME = "table_name";

public void delete(Context mContext){
        synchronized(Lock) {
            SQLiteDatabase db  = mContext.openOrCreateDatabase(DATABASE_NAME, Context.MODE_PRIVATE, null);
            db.delete(TABLE_NAME, null, null);
            db.close();
        }
    }

public void insert(Context mContext){
        synchronized(Lock) {
            SQLiteDatabase db  = mContext.openOrCreateDatabase(DATABASE_NAME, Context.MODE_PRIVATE, null);
            db.insert(TABLE_NAME, ..., ...);
            db.close();
        }
    }

}
```

Hope this would help Anyone in future :)

SQLite exception: Database is locked issue

Solution

Problem