Here is the DataBase CRUD Tutorial for Android.
First of all create the SQLite DB and paste in the assets folder.
See Blog for creation of SQLite DB https://mfarhan133.wordpress.com/2010/10/24/working-with-sqlite-db-tutorial/
Use DBAdapter Class for DB connectivity and CRUD manipulation.
Its functions details are commented in class itself.
You can download its complete source code from here.
Select
First of all on the start of application(Splash) call createDataBase() function to create and copy database from assets folder(Select in my case). After first time creation of DB used DB will be now on “/data/data/mypackagename/database/” path.
public ArrayList getUsers(){
DBAdapter dbAdapter=DBAdapter.getDBAdapterInstance(this);
try {
dbAdapter.createDataBase();
} catch (IOException e) {
Log.i("*** select ",e.getMessage());
}
dbAdapter.openDataBase();
String query="SELECT * FROM user;";
ArrayList> stringList = dbAdapter.selectRecordsFromDBList(query, null);
dbAdapter.close();
ArrayList usersList = new ArrayList();
for (int i = 0; i < stringList.size(); i++) {
ArrayList list = stringList.get(i);
UserBO user = new UserBO();
try {
user.id = Integer.parseInt(list.get(0));
user.name = list.get(1);
user.age = Long.parseLong(list.get(2));
} catch (Exception e) {
Log.i("***" + Select.class.toString(), e.getMessage());
}
usersList.add(user);
}
return usersList;
}
Insert
DBAdapter dbAdapter = DBAdapter.getDBAdapterInstance(Insert.this);
dbAdapter.openDataBase();
ContentValues initialValues = new ContentValues();
initialValues.put("name", etName.getText().toString());
initialValues.put("age", etAge.getText().toString());
long n = dbAdapter.insertRecordsInDB("user", null, initialValues);
Toast.makeText(Insert.this, "new row inserted with id = " + n, Toast.LENGTH_SHORT).show();
Update
DBAdapter dbAdapter = DBAdapter.getDBAdapterInstance(Update.this);
dbAdapter.openDataBase();
ContentValues initialValues = new ContentValues();
initialValues.put("name", etName.getText().toString());
initialValues.put("age", etAge.getText().toString());
String id = etId.getText().toString();
String [] strArray = {""+id};
long n = dbAdapter.updateRecordsInDB("user", initialValues, "id=?", strArray);
Toast.makeText(Update.this, n+" rows updated", Toast.LENGTH_SHORT).show();
Delete
DBAdapter dbAdapter = DBAdapter.getDBAdapterInstance(Delete.this);
dbAdapter.openDataBase();
String id = etId.getText().toString();
String [] strArray = {""+id};
long n = dbAdapter.deleteRecordInDB("user", "id = ?", strArray);
Toast.makeText(Delete.this, n+" rows effected", Toast.LENGTH_SHORT).show();
DBAdapter.java
public class DBAdapter extends SQLiteOpenHelper {
private static String DB_PATH = "";
private static final String DB_NAME = "user.sqlite";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static DBAdapter mDBConnection;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
private DBAdapter(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
DB_PATH = "/data/data/"
+ context.getApplicationContext().getPackageName()
+ "/databases/";
// The Android's default system path of your application database is
// "/data/data/mypackagename/databases/"
}
/**
* getting Instance
* @param context
* @return DBAdapter
*/
public static synchronized DBAdapter getDBAdapterInstance(Context context) {
if (mDBConnection == null) {
mDBConnection = new DBAdapter(context);
}
return mDBConnection;
}
/**
* Creates an 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 {
// By calling following method
// 1) an empty database will be created into the default system path of your application
// 2) than we overwrite that database with our database.
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_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
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();
}
/**
* Open the database
* @throws SQLException
*/
public void openDataBase() throws SQLException {
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
/**
* Close the database if exist
*/
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
/**
* Call on creating data base for example for creating tables at run time
*/
@Override
public void onCreate(SQLiteDatabase db) {
}
/**
* can used for drop tables then call onCreate(db) function to create tables again - upgrade
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// ----------------------- CRUD Functions ------------------------------
/**
* This function used to select the records from DB.
* @param tableName
* @param tableColumns
* @param whereClase
* @param whereArgs
* @param groupBy
* @param having
* @param orderBy
* @return A Cursor object, which is positioned before the first entry.
*/
public Cursor selectRecordsFromDB(String tableName, String[] tableColumns,
String whereClase, String whereArgs[], String groupBy,
String having, String orderBy) {
return myDataBase.query(tableName, tableColumns, whereClase, whereArgs,
groupBy, having, orderBy);
}
/**
* select records from db and return in list
* @param tableName
* @param tableColumns
* @param whereClase
* @param whereArgs
* @param groupBy
* @param having
* @param orderBy
* @return ArrayList>
*/
public ArrayList> selectRecordsFromDBList(String tableName, String[] tableColumns,
String whereClase, String whereArgs[], String groupBy,
String having, String orderBy) {
ArrayList> retList = new ArrayList>();
ArrayList list = new ArrayList();
Cursor cursor = myDataBase.query(tableName, tableColumns, whereClase, whereArgs,
groupBy, having, orderBy);
if (cursor.moveToFirst()) {
do {
list = new ArrayList();
for(int i=0; i 0;
}
/**
* This function used to update the Record in DB.
* @param tableName
* @param initialValues
* @param whereClause
* @param whereArgs
* @return 0 in case of failure otherwise return no of row(s) are updated
*/
public int updateRecordsInDB(String tableName,
ContentValues initialValues, String whereClause, String whereArgs[]) {
return myDataBase.update(tableName, initialValues, whereClause, whereArgs);
}
/**
* This function used to delete the Record in DB.
* @param tableName
* @param whereClause
* @param whereArgs
* @return 0 in case of failure otherwise return no of row(s) are deleted.
*/
public int deleteRecordInDB(String tableName, String whereClause,
String[] whereArgs) {
return myDataBase.delete(tableName, whereClause, whereArgs);
}
// --------------------- Select Raw Query Functions ---------------------
/**
* apply raw Query
* @param query
* @param selectionArgs
* @return Cursor
*/
public Cursor selectRecordsFromDB(String query, String[] selectionArgs) {
return myDataBase.rawQuery(query, selectionArgs);
}
/**
* apply raw query and return result in list
* @param query
* @param selectionArgs
* @return ArrayList>
*/
public ArrayList> selectRecordsFromDBList(String query, String[] selectionArgs) {
ArrayList> retList = new ArrayList>();
ArrayList list = new ArrayList();
Cursor cursor = myDataBase.rawQuery(query, selectionArgs);
if (cursor.moveToFirst()) {
do {
list = new ArrayList();
for(int i=0; i<cursor.getColumnCount(); i++){
list.add( cursor.getString(i) );
}
retList.add(list);
} while (cursor.moveToNext());
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
return retList;
}
}
Related Blog http://www.screaming-penguin.com/node/7742
