To USE LINKER IN OTHER UI CLASSES
(A working example of this is in the AddAccount class)

- class must import java.sql.*

- create method for SQL functionality:
    public void testDB() throws SQLException{
        Connection conn = get_connection();
        Statement stmt = conn.createStatement();
        String sql = "SELECT * FROM Users where Username = ?";
        PreparedStatement prepared_statement = conn.prepareStatement(sql);
        String username = "SuperKoolUser91";
        prepared_statement.setString(1, username);

        ResultSet rs = prepared_statement.executeQuery();
        ResultSetMetaData rsmd = rs.getMetaData();
        conn.close();
        }
   
 - to call SQL method :
        try {
          testDB();
        } catch (SQLException e1) {
          e1.printStackTrace();