Java mysql, Simple update with PreparedStatement has syntax error -

this code has sort of simple syntax error. i've fought hours , give up. can spot it? bet it's easy. thanks!

when update firstname john, no problem. when try update commented out line lastname too, syntax error.

import java.sql.*;  public class updatetester {     public static void main(string[] args) {        try {           connect connect = new connect();          connection connection = connect.getconnection();           try {              string sql        = "update student set firstname = ? "                      + " studentid = 456987";              //string sql     = "update student set firstname = ? "             //       + " set lastname = ?, "             //       + " studentid = 456987";              preparedstatement pst = connection.preparestatement(sql);             pst.setstring(1, "john");              //pst.setstring(2, "johnson");              pst.executeupdate();             system.out.println("updated successfully!");              connection.close();           } catch (sqlexception e) {             system.out.println("exception 1!");             e.printstacktrace();          }       } catch (exception e) {          system.out.println("exception 2!");          e.printstacktrace();       }    } } 

column names correct. updating lastname on it's own works correctly too. update fails syntax error when trying both, in commented out lines.

3 issues:

• the set keyword can appear once in update statement:
• comma before second parameter missing
• unnecessary comma before clause

the corrected syntax:

string sql     = "update student set firstname = ?, "                + " lastname = ? "                + " studentid = 456987"; 

sql reference