Retreive data from sqlite databse and update it

I am trying to retrieve a table user and trying to update one of the column of the user table later on.

I got most of the part like inserting user data to table and retrieving it back but i am not able to update one of the column.

DBhelper.class:

 String CREATE_USER_CONTACTS_TABLE = "CREATE TABLE " + TABLE_USER + "("
            + USER_ID + " INTEGER PRIMARY KEY   AUTOINCREMENT," + USER_NAME 
       + " TEXT,"
            + USER_PH_NO + " TEXT" + USER_DISPLAY_NAME + " TEXT" +  
            USER_DISPLAY_PICTURE + " TEXT" + ")";
    db.execSQL(CREATE_USER_CONTACTS_TABLE);


public void addUser(Database_Contact contact) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(USER_NAME, contact.get_owner_name());
    values.put(USER_PH_NO, contact.get_owner_phone_number());

    // Inserting Row
    db.insert(TABLE_USER, null, values);
    db.close(); // Closing database connection
}
public List<Database_Contact> getAllDatabase_Users() {
    List<Database_Contact> userList = new ArrayList<Database_Contact>();
    // Select All Query
    String selectQuery = "SELECT  * FROM " + TABLE_USER;

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Database_Contact contact = new Database_Contact();
            contact.set_user_id(Integer.parseInt(cursor.getString(0)));
            contact.set_owner_name(cursor.getString(1));
            contact.set_owner_phone_number(cursor.getString(2));
            // Adding contact to list
            userList.add(contact);
        } while (cursor.moveToNext());
    }

    // return contact list
    return userList;
}
public int setDisplayImage(long id,String path) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(USER_DISPLAY_PICTURE, path);
    // updating row
    return db.update(TABLE_USER, values, USER_ID +"="+id,null);
}

DatabaseContact.class:

public class Database_Contact {

//private variables


int _user_id;
String _display_name;
String _display_picture;
String _owner_phone_number;
String _owner_name;



public int get_user_id() {
    return _user_id;
}

public void set_user_id(int _user_id) {
    this._user_id = _user_id;
}




public String get_display_name() {
    return _display_name;
}

public void set_display_name(String _display_name) {
    this._display_name = _display_name;
}

public String get_display_picture() {
    return _display_picture;
}

public void set_display_picture(String _display_picture) {
    this._display_picture = _display_picture;
}

public String get_owner_phone_number() {
    return _owner_phone_number;
}

public void set_owner_phone_number(String _owner_phone_number) {
    this._owner_phone_number = _owner_phone_number;
}

public String get_owner_name() {
    return _owner_name;
}

public void set_owner_name(String _owner_name) {
    this._owner_name = _owner_name;
}

}

Mainactivity.class:

mydb = new DBHelper(this);
    List<Database_conytact> images = mydb.getAllDatabase_Users();
    mydb.setDisplayImage(images.get(0).get_user_id(), "String");