Update multiple rows with pdo and checkboxes

Question

Im trying to create a message inbox with a multi delete option. the user selects multiple selectboxes and they will be posted via a submit button. so the post values will be

message[] 1
message[] 2
submit delete

these are the checkboxes that are beeing used:

message id1
<input type='checkbox' id='{inbox_id}' name='message[]' value='{$inbox_id}'/>
message id2
<input type='checkbox' id='{inbox_id}' name='message[]' value='{$inbox_id}'/>
<input class='button' type='submit' value='delete' name='submit'>

This is the code where the post is beeing processed:

else if($_GET['p'] == "del") {

//some user checks

$message_del=$_POST['message'];
$N = count($message_del);
for($i=0; $i < $N; $i++)
{
    $result = $db->prepare("UPDATE `messages` SET `outbox`=0 AND `inbox`=0 WHERE `id`= :upid");
    $result->bindParam(':upid', $message_del[$i]);
    $result->execute();
}

  echo "messages archived";

  }else{echo "Your TV is lonely"; }

this is the database with 6 messages:

#   Name    Type        Collation       Attributes  Null    Default Extra
1   id      int(9)                      No          None    AUTO_INCREMENT
2   ip      varchar(255)utf8_unicode_ci No      
3   time    datetime                    Yes         NULL    
4   from    varchar(16) utf8_unicode_ci Yes         NULL    
5   to      varchar(16) utf8_unicode_ci Yes         NULL    
6   subject varchar(50) utf8_unicode_ci No      
7   message text        utf8_unicode_ci No          None    
8   read    int(1)          No  0   
9   inbox   int(1)          Yes 1   
10  outbox  int(1)          Yes 1   



id              ip        time  from    to          subject message read inbox outbox
1   00.00.00.00 10-3-2014 19:00 sender  receiver    subject message 1    1     0
2   00.00.00.00 11-3-2014 19:00 sender  receiver    subject message 1    1     0
3   00.00.00.00 12-3-2014 19:00 sender  receiver    subject message 1    1     0
4   00.00.00.00 13-3-2014 19:00 sender  receiver    subject message 0    1     0
5   00.00.00.00 14-3-2014 19:00 sender  receiver    subject message 1    0     1
6   00.00.00.00 15-3-2014 19:00 sender  receiver    subject message 0    0     1

but somehow (i guess) the query doesnt run. i'm afraid i forgot something simple.

Answer 1

This is the single-table syntax of UPDATE :

UPDATE [LOW_PRIORITY] [IGNORE] table_reference
    SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
    [WHERE where_condition]
    [ORDER BY ...]
    [LIMIT row_count]

When you say SET outbox=0 AND inbox=0 , that is still valid syntax, but does something different than what you probably expect.