Question

I want my Onclick method that is used used to insert data into a database to first check if data exist. If there is data, a toast message appears. how can I accomplish this. My OnClick is below. I just it to verify there is a username and password. If there is, the user receives a toast.

 @Override
public void onClick (View v) {

    rUsername = rName.getText().toString();
    rPasscode = rCode.getText().toString();

    RegDetails regDetails = new RegDetails();
    regDetails.setrName(bundleRegName);
    regDetails.setpCode(bundleRegCode);
    if(v.getId()==R.id.rtn_button){
        finish();

    }else if(v.getId()==R.id.reg_button){
        insertCredentials(regDetails);
    }
}
    private void insertCredentials(RegDetails regDetails){

        LoginDB androidOpenDBHelper = new LoginDB(this);
        SQLiteDatabase sqliteDB = androidOpenDBHelper.getWritableDatabase();

        ContentValues contentValues = new ContentValues();
        contentValues.put(LoginDB.COLUMN_NAME_USERNAME, rUsername);
        contentValues.put(LoginDB.COLUMN_NAME_PASSWORD, rPasscode);

        long affectedColumnid = sqliteDB.insert(LoginDB.TABLE_NAME_CREDENTIALS, null, contentValues);

        Toast.makeText(getApplicationContext(), "Credentials Saved! Please login" + affectedColumnid, Toast.LENGTH_SHORT).show();
        sqliteDB.close();
        finish();
    }   

  }

Answer 1

The sqliteDB.insert return long value on success and -1 on error. The long value indicates the row number for newly inserted row in db. You can check this return value and display toast accordingly.

Please look at the detailed explanation here, http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#insert(java.lang.String, java.lang.String, android.content.ContentValues)

In short, modify your code to be like this,

private void insertCredentials(RegDetails regDetails){

    LoginDB androidOpenDBHelper = new LoginDB(this);
    SQLiteDatabase sqliteDB = androidOpenDBHelper.getWritableDatabase();

    ContentValues contentValues = new ContentValues();
    contentValues.put(LoginDB.COLUMN_NAME_USERNAME, rUsername);
    contentValues.put(LoginDB.COLUMN_NAME_PASSWORD, rPasscode);

    long affectedColumnid = sqliteDB.insert(LoginDB.TABLE_NAME_CREDENTIALS, null, contentValues);
    if(affectedColumnid != -1){
    Toast.makeText(getApplicationContext(), "Credentials Saved! Please login" + affectedColumnid, Toast.LENGTH_SHORT).show();
     }else{
     // Display error dialog or smthg
     }
    sqliteDB.close();
    finish();
}