Modify rule S6909: Fix errors in code examples (#4008)

Author: leonardo-pilastri-sonarsource

rules/S6909/java/rule.adoc

@@ -27,7 +27,7 @@ public class DatabaseExample {
     public void updateTodayOrders(Connection connection, List<Order> orders) {
             Date today = java.sql.Date.valueOf(LocalDate.now());
             String insertQuery = "INSERT INTO Order (id, price, executionDate) VALUES (?, ?, ?)";
-            PreparedStatement preparedStatement = connection.prepareStatement(SQL_INSERT);
+            PreparedStatement preparedStatement = connection.prepareStatement(insertQuery);
 
             for(Order order: orders) {
                 preparedStatement.setString(1, order.id());
@@ -50,10 +50,9 @@ public class DatabaseExample {
     public void updateTodayOrders(Connection connection, List<Order> orders) {
             Date today = java.sql.Date.valueOf(LocalDate.now());
             String insertQuery = "INSERT INTO Order (id, price, executionDate) VALUES (?, ?, ?)";
-            preparedStatement.setDate(3, today); // Compliant
-
-            PreparedStatement preparedStatement = connection.prepareStatement(SQL_INSERT);
+            PreparedStatement preparedStatement = connection.prepareStatement(insertQuery);
 
+            preparedStatement.setDate(3, today); // Compliant
             for(Order order: orders) {
                 preparedStatement.setString(1, order.id());
                 preparedStatement.setString(2, order.price());