Tutorial MySQL - Update player's old name with new name via MYSQL

I'm using Husky's MySQL for example but it should work with any MySQL library.

MAKE SURE THAT THE PLAYER UUID IS PRIMARY AND UNIQUE

First we need to create 2 queries one that selects from the users profile and one that updates their name.

Code:

       String uuid = player.getUniqueId().toString();
        ResultSet query = sql.sql.querySQL("SELECT * FROM `profiles` WHERE `UUID`= '" + uuid + "';");
        PreparedStatement pquery = sql.c.prepareStatement("UPDATE `profiles` SET Name = ? WHERE UUID = ?");

We're going to use the PlayerJoinEvent to detect the player name change

Code:

    public void onJoin(PlayerJoinEvent e) throws Exception {
        Player player = e.getPlayer();

        String uuid = player.getUniqueId().toString();

        ResultSet query = sql.sql.querySQL("SELECT * FROM `profiles` WHERE `UUID`= '" + uuid + "';");
        PreparedStatement pquery = sql.c.prepareStatement("UPDATE `profiles` SET Name = ? WHERE UUID = ?");

    }

Now we're going to actual detect if their uuid exists in the database and check if they changed their name or not and update accordingly

Code:

        if ( query.next() )
        {
            if ( query.getString("Name").equals(player.getName()) )
            {
                player.sendMessage("You haven't changed your name");

            } else {

                Bukkit.broadcastMessage(ChatColor.YELLOW + query.getString("Name") + " has changed his name to " + player.getName()); // Broadcast if they changed there name
                pquery.setString(1, player.getName());
                pquery.setString(2, uuid);
                pquery.executeUpdate(); // EXECUTE THE UPDATE SO THE CHANGE CAN BE APPLIED ON THE DATABASE
                pquery.close(); // MAKE SURE YOU CLOSE THE QUERIES you don't want a shit ton of queries running
                query.close();

            }

        }

Final Result

Code:

    public void onJoin(PlayerJoinEvent e) throws Exception {
        Player player = e.getPlayer();

        String uuid = player.getUniqueId().toString();

        ResultSet query = sql.sql.querySQL("SELECT * FROM `profiles` WHERE `UUID`= '" + uuid + "';");
        PreparedStatement pquery = sql.c.prepareStatement("UPDATE `profiles` SET Name = ? WHERE UUID = ?");

        // Name Change Detection
        if ( query.next() ) // Checks if the players uuid exists
        {
            if ( query.getString("Name").equals(player.getName()) ) // Checks if the players name is the same as the one on the database
            {
                player.sendMessage("You haven't changed your name");

            } else {

                Bukkit.broadcastMessage(ChatColor.YELLOW + query.getString("Name") + " has changed his name to " + player.getName());
                pquery.setString(1, player.getName());
                pquery.setString(2, uuid);
                pquery.executeUpdate();
                pquery.close();
                query.close();

            }

        }
    }