java - SQLException related to insert database values using ArrayList -

iam new java , trying develop small swing app, have inquiry model class containing getters , setters , constructions , iam getting input user in jframe.

im getting error java.sql.sqlexception: @ least 1 parameter current statement uninitialized " when run code.

  public class makeandreply_inquiry {     string in_id=null;    string in_title=null;    string in_msg=null;    date in_date;      connection con;     public void insertinquirytodb(arraylist<inquiry> arrlist){         try {         dateformat dateformat = new simpledateformat("yyyy/mm/dd hh:mm:ss");          in_date = new date();         system.out.println(dateformat.format(in_date)); //2014/08/06 15:59:48         iterator<inquiry> iter = arrlist.iterator();             while(iter.hasnext())             {             inquiry inq = iter.next();               in_id=inq.getin_id();               in_title=inq.getin_title();               in_msg=inq.getin_msg();             }             con = new dbconnector().connect();             system.out.println("nside insert inq method "+in_id +in_title+in_msg);             string sq = "insert inquiry (in_id,in_title,in_msg,in_date)values(?,?,?,?)";             preparedstatement pr = con.preparestatement(sq);             pr.executeupdate();           } catch (sqlexception ex) { ex.printstacktrace();          }     } } 

can 1 please me solve this.

you not setting value in

        string sq = "insert inquiry (in_id,in_title,in_msg,in_date)values(?,?,?,?)";         preparedstatement pr = con.preparestatement(sq);          // set values here         pr.executeupdate();