I've used SQLite DB in different applications and my approach is:
I create a DB using a Mozilla extension SQLite Manager, saving the .sqlite in the application asset folder.
Then i write the class DatabaseHelper
public class DataBaseHelper extends SQLiteOpenHelper{
private static String DB_PATH = "/data/data/your.package.name/databases/";
private static String DB_NAME = "/*name of your sqlite file, ex Contacts.sqlite*/";
private SQLiteDatabase LuckyDB;//name of your DB
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}catch(SQLiteException e){
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
LuckyDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if(LuckyDB != null)
LuckyDB.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
/** Crea (se necessario) il database e restituisce l'oggetto database **/
public SQLiteDatabase getDb()
{
try {
this.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
this.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
return LuckyDB;
}
}
When you need to use it, you can do so:
DataBaseHelper myDbHelper = new DataBaseHelper(getApplicationContext());
SQLiteDatabase db = myDbHelper.getDb();
You should use Cursor,rawQuery and while loop to get, add or delete datas from your DB.
Hope it helps ya!
