updating method using content values

Question

Helper

public boolean mMessagesSent(String ID,int Data) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(KEY_ID, ID);
    contentValues.put(KEY_MESSAGES_SENT, Data);
    db.update(TABLE_USER_DATA, contentValues, null, null);
    return true;
}     

Activity

mainData.mTotalMessages("MyData", +1);
        mainData.mTotalMessagesSent("MyData",+1);
        mainData.mMessages(MessageRecieverId,+1);
        mainData.mMessagesSent(MessageRecieverId,+1);

Is this the correct method to update data... I want to increase the int value of data by 1 so i have put +1 but still the value is empty when i retrieve data

CODE AFTER FOLLOWING FIRST ANSWER

public boolean mMessagesSent(String ID,int Data) {
    MainData mainData = new MainData(getApplicationContext());
    SQLiteDatabase db = mainData.getWritableDatabase();
    String newId = ID;
    int newData = Data;
    MainData helper = new MainData(this); //Change the name to your Helper Class name
    Cursor data = helper.getData();
    while (data.moveToNext()) {
        newId = data.getString(data.getColumnIndex("Data"));
        newData = data.getInt(data.getColumnIndex("TotalMessagesSent"));
    }
    ContentValues contentValues = new ContentValues();
    contentValues.put(KEY_DATA, newId);
    contentValues.put(KEY_MESSAGES_SENT, (newData + 1)); //Change the value of newData(which is actually your old value) by incrementing
    db.update(TABLE_USER_DATA, contentValues, null, null);
    return true;
}

FETCHING

final MainData myDBHlpr = new MainData(getActivity());

    Cursor csr = myDBHlpr.getAllQuestions(getActivity());
    while (csr.moveToNext()) {

        mTotalMessagesSent.setText(csr.getString(1));
        mTotalMessagesRecieved.setText(csr.getString(csr.getColumnIndex("TotalMessagesRecieved")));
        mTotalMessages.setText(csr.getString(csr.getColumnIndex("TotalMessages")));

    }

        csr.close();

Answer 1

Is this the correct method to update data... I want to increase the int value of data by 1 so i have put +1 but still the value is empty when i retrieve data

If you meant to increase the existing value of data by once each time you call the function mMessagesSent()

You can consider to first take the value from the database if it exists, and increment the value. Create a function in Helper as shown below

public Cursor getData(){

    SQLiteDatabase db = this.getWritableDatabase();
    String query = "SELECT * FROM " + TABLE_NAME;

    return db.rawQuery(query, null);
}

This will return a Cursor to the Database, to read the values in the database. Do not put the function mMessagesSent in Helper class, put it in the Activity. Now in your mMessagesSent function, call the above function getData() as shown

public void mMessagesSent() {
SQLiteDatabase db = this.getWritableDatabase();
String newId = "default value whatever you have specified";//These two lines may be removed and put outside. If you already have it, then 
int newData = 0;                                           //not required to declare here at all, just replace with those variable names
HelperClassName helper = new HelperClassName(this); //Change the name to your Helper Class name
Cursor data = helper.getData();
while(data.moveToNext()){
    newId = data.getString(0);
    newData = data.getInt(1);
}
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_ID, ID);
contentValues.put(KEY_MESSAGES_SENT, (newData+1)); //Change the value of newData(which is actually your old value) by incrementing
long returnVariable = db.update(TABLE_USER_DATA, contentValues, null, null);
if(returnVariable == -1){
    //-1 means there was an error updating the values
}
else{
//the return value if successful will be number of rows affected by the update
}
} 

I hope you got your answer.