I have successfully implemented a prepopulated database using SQLite Asset Helper and performed a query to list the names of my objects in the table using this tutorial . I would however like to add CRUD functions to the android application to Add, Delete and Insert new objects. How can I do that?
DatabaseOpenHelper.java
import android.content.Context;
import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;
public class DatabaseOpenHelper extends SQLiteAssetHelper {
private static final String DATABASE_NAME = "camera1.db";
private static final int DATABASE_VERSION = 1;
public DatabaseOpenHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
}
DatabaseAccess.java
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.List;
public class DatabaseAccess {
private SQLiteOpenHelper openHelper;
private SQLiteDatabase database;
private static DatabaseAccess instance;
/**
* Private constructor to aboid object creation from outside classes.
*
* @param context
*/
private DatabaseAccess(Context context) {
this.openHelper = new DatabaseOpenHelper(context);
}
/**
* Return a singleton instance of DatabaseAccess.
*
* @param context the Context
* @return the instance of DabaseAccess
*/
public static DatabaseAccess getInstance(Context context) {
if (instance == null) {
instance = new DatabaseAccess(context);
}
return instance;
}
/**
* Open the database connection.
*/
public void open() {
this.database = openHelper.getWritableDatabase();
}
/**
* Close the database connection.
*/
public void close() {
if (database != null) {
this.database.close();
}
}
/**
* Read all quotes from the database.
*
* @return a List of quotes
*/
public List<String> getQuotes() {
List<String> list = new ArrayList<>();
Cursor cursor = database.rawQuery("SELECT cameraname FROM camera", null);
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
list.add(cursor.getString(0));
cursor.moveToNext();
}
cursor.close();
return list;
}
}
To do this you need to copy your database into a device:
private static void copyDatabase(Context context) throws IOException {
InputStream myInput = context.getResources().openRawResource(
R.raw.database);
String outFileName = getFullDbName(context);
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
Then just open the database as usual:
mSqlite = new SqliteHelper(context, getFullDbName(context), null,
DATABASE_VERSION);
After that you can just write whatever raw query you want.
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