Query executed twice (by error) in Java with unwanted values

Question

I'm using JFreeChart to create a chart in Java and MySQL.

When I try to insert my values in another table the query seems to be executed twice since I end up with the same timestamps multiple times...

Here's a part of my code :

    private JDBCXYDataset createDataset() {
        try {
            Connection conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:bd?serverTimezone=UTC","MySQL", "MySQL");
           
            conn.setAutoCommit(false);
            SQLException savedException = null;
            
            Statement st = conn.createStatement();
            st.execute("DROP TABLE IF EXISTS test ");
            st.execute("create table test(Table timestamp, Table float,Table float)");
            
            String Date_Debut = "2020-06-25 00:00:00";
            String Date_Fin = "2020-06-26 00:00:00";
            String sql1 = "INSERT INTO test (Table ,Table ,Table ) "
                    + "SELECT Table ,Table ,Table "
                    + "FROM Table "
                    + "WHERE Table BETWEEN ? AND ? ";
            
           try ( PreparedStatement ps = conn.prepareStatement(sql1)){
           
            ps.setString(1,Date_Debut);
            ps.setString(2, Date_Fin);
         
            ps.executeUpdate();
            ps.close();
            
            JDBCXYDataset jds = new JDBCXYDataset(conn);
            
            st.close();
            
            jds.executeQuery("SELECT Table ,Table ,Table FROM test");
            
            
            conn.commit();
            return jds;
           } catch (SQLException ex) {
               savedException = ex;
               conn.rollback();
           } finally {
               conn.setAutoCommit(true);
               if(savedException != null) {
                   throw savedException;
               }
           }
       } catch (SQLException ex1) {
           
       }
        return null;
    }

EDIT : Actually it seems like the errors where comming directly from the database, the moderators can delete this post if they want. However I keep Trashgod's response validated as it was more than helpful. For everyone that might come here with a similar issue, inspect in detail your database first to see if it isn't comming from there instead of your code.

Answer 1

Chasing down anomalies in data is arduous, but JFreeChart can at least make the result easier to visualize. Some heuristics for testing:

• To verify that the the presumed duplicates in your tabular listing are indeed duplicates, format the timestamps to include milliseconds, eg add an S to a SimpleDateFormat or A to a DateTimeFormatter .

• For study, temporarily pass the query directly to JDBCXYDataset , and add an ORDER BY clause (untested):

   jds.executeQuery( "SELECT Date_Heure, PV, SV FROM cmd3 " + "WHERE Date_Heure BETWEEN " + "2020-06-25 00:00:00 AND 2020-06-26 00:00:00 " + "ORDER BY Date_Heure");

• Enable tooltips in your ChartFactory , as you did here , to see data values in situ . This may suggest additional conditions for your WHERE clause, eg PV BETWEEN 5.1 AND 5.9 .

• Use the interactive JFreeChart pan/zoom controls, discussed here to examine the data; add suitable buttons, shown here , if it will make it easier for colleagues to see your findings.

• By design, JDBCXYDataset executes a query defined by a String . If your design needs to display data from a query defined by a PreparedStatement , you can use the existing implementation as a guide.

   public class PreparedDataset extends AbstractXYDataset implements XYDataset, TableXYDataset, RangeInfo { private final PreparedStatement ps; public PreparedDataset(PreparedStatement ps) { this.ps = ps; } … }