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.

you need to show the error log to be sure that something is wrong.

In the mean time, do the below if there are no error logs :

Get the actual {sql} query text that is formed in your code and run that directly on the database and see if it works normally. If it doesn't work then the issue you are having is with the query string that you are sending to the database.

Let us know if this works, you code is actually looking okay for a normal data connectivity statement.

ehmmmm you deducted the value in code and not in db, where you expecting the value to deduct without a sql to do that.