How can i clear a SQLite database each time i start my app
- by AndroidUser99
Hi, i want that each time i start my app my SQLite database get's cleaned
for this, i need to make a method on my class MyDBAdapter.java
code examples are welcome, i have no idea how to do it
this is the dbadapter/helper i'm using:
public class MyDbAdapter {
private static final String TAG = "NotesDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_NAME = "gpslocdb";
private static final String PERMISSION_TABLE_CREATE = "CREATE TABLE permission ( fk_email1 varchar, fk_email2 varchar, validated tinyint, hour1 time default '08:00:00', hour2 time default '20:00:00', date1 date, date2 date, weekend tinyint default '0', fk_type varchar, PRIMARY KEY (fk_email1,fk_email2))";
private static final String USER_TABLE_CREATE = "CREATE TABLE user ( email varchar, password varchar, fullName varchar, mobilePhone varchar, mobileOperatingSystem varchar, PRIMARY KEY (email))";
private static final int DATABASE_VERSION = 2;
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(PERMISSION_TABLE_CREATE);
db.execSQL(USER_TABLE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS user");
db.execSQL("DROP TABLE IF EXISTS permission");
onCreate(db);
}
}
/**
* Constructor - takes the context to allow the database to be
* opened/created
*
* @param ctx the Context within which to work
*/
public MyDbAdapter(Context ctx) {
this.mCtx = ctx;
}
/**
* Open the database. If it cannot be opened, try to create a new
* instance of the database. If it cannot be created, throw an exception to
* signal the failure
*
* @return this (self reference, allowing this to be chained in an
* initialization call)
* @throws SQLException if the database could be neither opened or created
*/
public MyDbAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
public long createUser(String email, String password, String fullName, String mobilePhone, String mobileOperatingSystem)
{
ContentValues initialValues = new ContentValues();
initialValues.put("email",email);
initialValues.put("password",password);
initialValues.put("fullName",fullName);
initialValues.put("mobilePhone",mobilePhone);
initialValues.put("mobileOperatingSystem",mobileOperatingSystem);
return mDb.insert("user", null, initialValues);
}
public Cursor fetchAllUsers() {
return mDb.query("user", new String[] {"email", "password", "fullName", "mobilePhone", "mobileOperatingSystem"}, null, null, null, null, null);
}
public Cursor fetchUser(String email) throws SQLException {
Cursor mCursor = mDb.query(true, "user", new String[] {"email", "password", "fullName", "mobilePhone", "mobileOperatingSystem"}
, "email" + "=" + email, null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
public List<Friend> retrieveAllUsers()
{
List <Friend> friends=new ArrayList<Friend>();
Cursor result=fetchAllUsers();
if( result.moveToFirst() ){
do{
//note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_TITLE)));
friends.add(new Friend(result.getString(result.getColumnIndexOrThrow("email")), "","","",""));
}while( result.moveToNext() );
}
return friends;
}
}
