通过user_id用PHP更新4个SQL字段

Question

Is this possible to update 4 different columns based on a person " user_id " within the code?

I know there are a few examples but I'm having trouble understanding them, if someone could give me an example of how this would be done, so I can change my code accordingly I would be very grateful.

The code below works to update field1 , but how can I tailor it to upload field2 , field3 and field4 also?

<?php
include 'inc/db-connect2.php' ;
$dbname = "dtarg";

mysql_select_db($dbname);

$username = $_GET["username"];
$bianca = $_GET["bianca"];
$carla = $_GET["carla"];
$caroline = $_GET["caroline"];
$carrieanne = $_GET["carrieanne"];
$catherine = $_GET["catherine"];
$frazer = $_GET["frazer"];
$jason = $_GET["jason"];
$jay = $_GET["jay"];
$jordan = $_GET["jordan"];
$kim = $_GET["kim"];
$lindsay = $_GET["lindsay"];
$natasha = $_GET["natasha"];
$steph = $_GET["steph"];
$toby = $_GET["toby"];



$namequery = "SELECT * FROM users WHERE name='$username'"; 
$nameresult = mysql_query($namequery) or die(mysql_error());
while($namerow = mysql_fetch_array($nameresult)){
        $userid = $namerow['user_id'];
        $shift = $namerow['shift'];

}
$addrecord="UPDATE users
    SET field1 = CASE user_id
    WHEN '18' THEN '$bianca'
    WHEN '19' THEN '$carla'
    WHEN '20' THEN '$caroline'
    WHEN '7' THEN '$carrieanne'
    WHEN '16' THEN '$catherine'
    WHEN '21' THEN '$frazer'
    WHEN '15' THEN '$jason'
    WHEN '5' THEN '$jay'
    WHEN '11' THEN '$jordan'
    WHEN '10' THEN '$kim'
    WHEN '25' THEN '$lindsay'
    WHEN '6' THEN '$natasha'
    WHEN '1' THEN '$steph'
    WHEN '4' THEN '$toby'


    END
    WHERE user_id IN (18,19,20,7,16,21,15,5,11,10,25,6,1,4)";



    if (!mysql_query($addrecord))
        {
          die('Error: ' . mysql_error());
        }   

   ?>

EDIT 2 - This code seems to update field1, to the same value as field2?

    $addrecord="UPDATE users
    SET field1 = CASE user_id
    WHEN '18' THEN '$bianca'
    WHEN '19' THEN '$carla'
    END ,

    field2 = CASE user_id
    WHEN '18' THEN '$bianca'
    WHEN '19' THEN '$carla'
    END



    WHERE user_id IN (18,19,20,7,16,21,15,5,11,10,25,6,1,4)";



    if (!mysql_query($addrecord))
        {
          die('Error: ' . mysql_error());
        }   

Answer 1

Yes, just add a comma and reuse the logic :

SET field1 = CASE user_id
                   WHEN '18' THEN '$bianca'
                   WHEN '19' THEN '$carla'
                   .... END ,
    field2 = CASE user_id
                   WHEN '18' THEN '$bianca'
                   WHEN '19' THEN '$carla'
                   .... END ,
   ....