code: public boolean executeCommand(String query) throws SQLException, ClassNotFoundException {
          if (!connected) {
              open();
          }
          Statement stmt = con.createStatement();
  
          return stmt.execute(query);
      }
docs: Execute the specified SQL command
  If the SQL connection if not open, it will be opened automatically
  
  @param query The specified query
  @return the ResultSet object. The returned ResultSet has to be closed manually.
  @throws java.sql.SQLException If a SQL error occurs
  @throws java.lang.ClassNotFoundException If the driver class does not exists