How to count data in Java MySQL

Question

How to count data in Java and MySQL? The final result is shown to me through JOptionpane but I got an error message with this code.

 try { DBConn.conn = DriverManager.getConnection(DBConn.Url, DBConn.User, DBConn.PWD);
          java.sql.Statement count = DBConn.conn.createStatement();
          String SQLCount = "select count(*) from datastudent where parklevel = 'Level 1' ";
                ResultSet rs = count.executeQuery(SQLCount);
                  while (rs.next()) {
                    JOptionPane.showMessageDialog(null,"number of existing parking is " + rs);
                }
            } catch (Exception e2) {
            //
            }
       }

http://stackoverflow.com/questions/3988788/what-is-a-stack-trace-and-how-can-i-use-it-to-debug-my-application-errors — isnot2bad, Nov 25 '13 at 18:08

score 1 · Answer 1 · answered Nov 25 '13 at 18:03

1

You should print rs.getInt (1). When you select a count of some data from some table, the result is returned as an integer column in the result set.

So try :

JOptionPane.showMessageDialog(null,"number of existing parking is " + rs.getInt (1));

answered Nov 25 '13 at 18:03

Eran

387,369
54
702
768

score 0 · Answer 2 · answered Nov 25 '13 at 18:09

0

try this. your query return only one value, so no need loop.

           ResultSet rs = count.executeQuery(SQLCount);
           rs.next();
           JOptionPane.showMessageDialog(null,"number of existing parking is " + rs.getInt(1));

answered Nov 25 '13 at 18:09

subash

3,116
3
18
22

score 0 · Answer 3 · answered Nov 25 '13 at 18:10

0

You're not reading any values from ResultSet, see javadocs. Needs rs.getInt(1)

answered Nov 25 '13 at 18:10

Konstantin

3,254
15
20

How to count data in Java MySQL

3 Answers3

Linked

Related