Hello my ogas at the top. I am just learning Java programming language and I have a project on medical store that I am working on but I have a little problem.
I created a button and I want the button to deduct the number of drugs order through a jtextfield but when ever I press the button it only places order but won't deduct any value from the db.
This is the code I used.

String val=jLabel5.getText();
String val1=Jtextfield5.getText();
int val2= Integer.parseInt(val1);

try{
String sql=" update druginfo set qty ='" +val1+"' where id='" +val+"' " ;
pst=conn.PrepareStatement(sql):
rst=pst.executeUpdate();

while(rst.next()) {
String add=rst.getInt("qty";

}
add-val2;

} catch(Exception e) {
JOptionPane.showMessageDialog(null, e);
}

But the code is not getting the job done. Please help a brother in need I have searched Google and found no reasonable answer.