在JTextfield中显示来自两个不同mysql表的数据

Question

 private void LoadDescription() {
        try {
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/ABEL?zeroDateTimeBehavior=convertToNull", "root", "");
            String sql = "SELECT DESCRIPTION FROM VOORRAADSYSTEEM JOIN STAMDATA ON ARTICLECODE = ARTICLENUMBER WHERE ARTICLECODE="+jComboBox1.getSelectedItem();
            pst = conn.prepareStatement(sql);
            rs = pst.executeQuery();
            pst.setString(2, sql);
            descriptionTxt.setText(rs.getString(sql));
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e);
        }
    }

此时此刻，我不太确定如何处理这个问题。我还打算尝试使用外键。如有任何帮助，不胜感激。

Answer 1

有更好的方法来处理你想做的事情。例如，您可以通过将表连接到一个公共列（ARTICLENUMBER和ARTICLECODE）上，然后显示它，从而通过一个查询获得所需的所有信息。

现在，看起来/听起来，您可能正试图通过两个查询获得所有信息。

但是，您的负载描述方法存在一些错误：

private void LoadDescription() {
    try {
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/ABEL?zeroDateTimeBehavior=convertToNull", "root", "");
        String sql = "SELECT DESCRIPTION FROM VOORRAADSYSTEEM JOIN STAMDATA ON ARTICLECODE = ARTICLENUMBER WHERE ARTICLECODE="+jComboBox1.getSelectedItem();
        ResultSet results = conn.createStatment().executeQuery(sql);

        if(results.next()) //make sure something was returned to avoid null pointer exception
            descriptionTxt.setText(rs.getString("DESCRIPTION"));
        else
            JOptionPane.showMessageDialog(null, "no results returned");
    } catch (Exception e) {
        JOptionPane.showMessageDialog(null, e);
    }
}