Question

Consider the following code:

String updatestmt = "UPDATE marketplaces.amazon_merchant_fulfilled_orders SET order_status = ? WHERE amazon_order_id=?;";

 Connection conn = connectToDatabase();
 PreparedStatement pstInsert = conn.prepareStatement(updatestmt);
 pstInsert.setString(1, orderId);
 pstInsert.setString(2, status);
 try {
     int rowsAffected = pstInsert.executeUpdate();
     System.out.println("Updated " + rowsAffected + " Line(s).");
 ...

When this code is executed, rowsAffected is always 0.

If I change updatestmt to :

"UPDATE marketplaces.amazon_merchant_fulfilled_orders SET order_status = '"+status+"' WHERE amazon_order_id='"+orderId+"';"; and remove the pstInsert.setString calls the code works fine.

My question is why am I unable to use prepared statements to update my database?

Platform: PostgreSQL 9.2 and Java 7

Answer 1

You’re setting the parameters in wrong order. Note:

UPDATE marketplaces.amazon_merchant_fulfilled_orders
SET order_status = ? WHERE amazon_order_id=?

And you’re sending

pstInsert.setString(1, orderId);
pstInsert.setString(2, status);

Change the order to make it work

pstInsert.setString(1, status);
pstInsert.setString(2, orderId);