How to get value from a sum on resultset and print on JOptionPane?

Asked Jan 22 '20 at 01:05

Active Jan 22 '20 at 01:05

Viewed 99 times

I'm trying to get the sum of a column but its printing only the value started in the variable

That's what i have:

              double sum = 0;
              PreparedStatement st = con.prepareStatement("SELECT SUM(REPLACE(`preço`, 'R$ ', '' )) AS valor FROM `vendatemp`");
              ResultSet rs = st.executeQuery();
              if(rs != null) { 
                  while(rs.next()) {
                      sum = rs.getDouble(1); 
                  } 
              }

              JOptionPane.showMessageDialog(null, "Valor total a pagar: " + sum);

I think the problem is around this "getDouble", but i can't find anything to replace

asked Jan 22 '20 at 01:05

Giuseppe Piovesan Savastano

is not the use of `REPLACE(\`preço\`, 'R$ ', '' )` indicating that this is a String value? How can you sum Strings values? – Scary Wombat Jan 22 '20 at 01:14
I searched and saw that it was possible to sum the values that are after these characters doing that, but maybe didn't worked – Giuseppe Piovesan Savastano Jan 22 '20 at 01:22
Have you tried doing so in a sql client? – Scary Wombat Jan 22 '20 at 01:28
@ScaryWombat yes, there the result was the expected, but in java i don't know where is my mistake, for this i imagined the error was on getDouble – Giuseppe Piovesan Savastano Jan 22 '20 at 01:32
Well either `null` or `0` is returned, or this code is not being entered into, or an Exception is thrown. Put some debugging into your code (or use a debugger) to find out what is happening. – Scary Wombat Jan 22 '20 at 01:35
in the sql client, the result was "42,67", that was the correct answer, back in the java app, the JOptionPane is showing 0 – Giuseppe Piovesan Savastano Jan 22 '20 at 01:46
After `sum = rs.getDouble(1);` add `System.out.println (sum);` - does it print ? – Scary Wombat Jan 22 '20 at 02:01

How to get value from a sum on resultset and print on JOptionPane?

0 Answers0