I want to to do the following but can't figure out how to do it in Java.

I retrieve information, including the primary key, from a database. Using this information, I load a comboBox. The user selects an item from the comboBox. Using that selection, I build an SQL join to retrieve additional information.

My Problem: I can't figure out how to keep track of the relationship between the items in the comboBox and the primary key.

Appreciate some help..



When you add an Object to the Combo Box, the toString() method is called and it displays that at the GUI: void addItem(Object anObject) The method Object getSelectedItem() gets you the item you have selected.

So create an object with all the info from the DB including the primary key:

class Data {
  private long id = 0L; // assuming this is the PK
  private Sting name = null;
  private int age = 0;

  public String toString() {
      return name;

Get the data from the DB, put each row in a Data object and put that object into a List (java.util.Vector).

Then add each of the objects from the List to Combo Box

Thank you very much for the response. Hopefully, I'll get a chance to try it today. I'll get back when I do. Thanks again.

I'm sorry. I guess I didn't completely understand what you told me. I use the excuse that I'm a newbie!! Nothing is displayed in the comboBox. It appears it has the correct number of items but the dropdown box is empty. Here's my code. Appreciate your comments.

/* This class holds the contents of the database ResultSet */
public class Data {

    private String author = null;     //  Author's name
    private long primaryKey = 0L;   // Primary Key

    public void setName(String n){
        author = n;

    public void setID(long id) {
        primaryKey = id;
    // When you add an Object to the Combo Box,
    // the toString() method is called and it displays that at the GUI:

    public String toString() {
        return author;

Data data = null;   // Create an object to hold the database information
        Vector dataList = new Vector();

        // Retrive a complete list of authors from the database
        // formatted last, first.

        resultSet = dbManage.Query(SELECT);       // Get the data from the database

        try {
            while (resultSet.next()) {
                data = new Data();          // Create a Data object

                data.setName(resultSet.getString("Name"));  // Save the author's name
                data.setID(resultSet.getLong("authorID"));  // Save the author ID

                dataList.add(data);     // add the data row to the list
        } catch (SQLException e) {

        for (int i = 0; i < dataList.size(); i++) {

            cboAuthors.addItem(dataList.get(i));    // add the list to the comboBox

The code in the previous post is okay. It was a user error on my part and I didn't catch it until my "edit post" time had expired. Sorry...

I still haven't tested retrieving the selected item. I'll get back when I have done that. Sorry for the bad post. And sorry I didn't catch until after the 30 minute edit time limit.

I retrieved the selected item into a "Data" object, which is the class I created to addItem the data. And there the row data was. Thank you.