{ // BAD: the category might have SQL special characters in it String category = System.getenv("ITEM_CATEGORY"); Statement statement = connection.createStatement(); String query1 = "SELECT ITEM,PRICE FROM PRODUCT WHERE ITEM_CATEGORY='" + category + "' ORDER BY PRICE"; ResultSet results = statement.executeQuery(query1); } { // GOOD: use a prepared query String category = System.getenv("ITEM_CATEGORY"); String query2 = "SELECT ITEM,PRICE FROM PRODUCT WHERE ITEM_CATEGORY=? ORDER BY PRICE"; PreparedStatement statement = connection.prepareStatement(query2); statement.setString(1, category); ResultSet results = statement.executeQuery(); }