Construct your query within the loop:

<?php
...
$id_array = $_POST['id'];
$name_array = $_POST['name'];
$age_array = $_POST['age'];

for (i < count($id_array); $i++) {
//count($id_array) --> if I input 4 fields, count($id_array) = 4)

   $id = mysql_real_escape_string($id_array[name = mysql_real_escape_string($name_array[age = mysql_real_escape_string($age_array[query .= "UPDATE member SET name = '$name', age = '$age' WHERE id = '$id';";
}

mysql_query($query);
}
...
?>

Hope that helps..!

I googled a lot the last days and a few times i´ve seen postings that say that the $wpdb->update function doens´t support multiple updates and that this is not well documented. -> Sorry i don´t have links anymore...

I think that this is true because i couldn´t get it to work and i found not a single example witch works this way. So i use this way now to update multiple rows and still be able to handle errors.

The function:

function update_queries( $queries ) {
    global $wpdb;

    // set array
    $error = array();

    // run update commands
    foreach( $queries as $query ) {
        $query = str_replace( '[wp-prefix]', $wpdb->prefix, $query );
        $last_error = $wpdb->last_error;
        $wpdb->query( $query );

        // fill array when we have an error
        if( (empty( $wpdb->result ) || !$wpdb->result ) && !empty( $wpdb->last_error ) && $last_error != $wpdb->last_error ) {
                $error[]= $wpdb->last_error." ($query)";
        }
    }

    // when we have an error
    if( $error ) {
        return $error;

    // when everything is fine
    }else{
        return false;
    }
}

If we want to update a few things:

// update database
$queries = array();
$queries[] = "UPDATE `[wp-prefix]table` SET `value` = '$value'  WHERE `name` = 'name';";
$queries[] = "UPDATE `[wp-prefix]table` SET `value` = '$value2'  WHERE `name` = 'name2';";
$error = update_queries( $queries );

// if we have an error
if( !empty( $error ) ) {
    .....

// when everything is fine
}else{
    .....
}

Your SQL looks syntactically correct (unless I've missed something simple). The actual problem is because you're using mysql_query() - which does not support multiple statements; therefore, you can't run two UPDATE queries in one with this method.

From the manual:

mysql_query() sends a unique query (multiple queries are not supported)

On the same note, the mysql_ methods are being deprecated so I (and the community) would suggest you update your code to use mysqli_ or PDO methods - both of which support multiple queries in a single statement.

If you need to stick with mysql_query() (instead of restructuring your entire application), just split the queries and run them back-to-back.

To do it in a single run of a query, you'd need to use a CASE and assemble the parameters programmatically. SQL doesn't support variadic prepared statements, and only simple values can be parameterized.

Alternatively, define a statement to only take data for one row at a time and run the query in a loop. Repeated execution is how prepared statements are designed to be used for cases like this.

try {
    $query = $db->prepare('UPDATE table SET a = ? WHERE b = ? AND c = 1');
    foreach ($as as $i => $a) {
        $query->execute(array($a, $bs[$i]));
    }
} catch (PDOException $e) {
    ...
}

I can suggest little more longer method, but work fine:

1. Load file into table, for example TableB (original in this case TableA), TableB has only PK - id

2. Update - before INSERT

   UPDATE TableA t1 INNER JOIN TableB t2 ON t1.id = t2.id
   

3. Insert

   INSERT INTO TableA 
   SELECT * 
   FROM TableB t1 
   WHERE NOT EXISTS 
         (SELECT id FROM TableA t2 WHERE t2.id = t1.id)
   

I prefer this way, because:

• it fast
• it flexible - steps in-dependent and logic for UPDATE/INSERT could be changed separately

Yes, that's possible - you can use INSERT ... ON DUPLICATE KEY UPDATE.

Using your example:

INSERT INTO table (id,Col1,Col2) VALUES (1,1,1),(2,2,3),(3,9,3),(4,10,12)
ON DUPLICATE KEY UPDATE Col1=VALUES(Col1),Col2=VALUES(Col2);

Use a case expression:

UPDATE $userName
SET P1 = case day
         when 'MON1' then '$p1MON'
         when 'TUE1' then '$p1TUE'
         when 'WED1' then '$p1WED'
         end
where day IN ('MON1', 'TUE1', 'WED1')

Yes, your thinking is correct. It should be something like this:

INSERT INTO settings (user_id, enabled, status)
SELECT user_id, enabled, status
FROM ... -- rest of your query here
ON DUPLICATE KEY UPDATE enabled = VALUES(enabled), status = VALUES(status)

VALUES(colname) in the ON DUPLICATE KEY UPDATE clause gets the value that would have been inserted if there hadn't been a dupliate.

OK, based on your comment, I think this may be what you want:

INSERT INTO settings (user_id, enabled, status)
SELECT :user_id, :enabled, :status
FROM ...
JOIN ...
JOIN ...
WHERE ...
ON DUPLICATE KEY UPDATE enabled = VALUES(enabled), status = VALUES(status)

If the join returns any rows, this will insert or update the specified row. If it doesn't find any rows, no insert/update will be done.

You should probably be using inner joins rather than left joins, if you don't want anything returned when there are no matches in the tables being joined with.

 $sql = "UPDATE `product_list` SET 
       `product_name` = '$product_name', 
       `product_category` = '$product_category', 
       `product_price` = '$product_price', 
       `product_description` = '$product_description', 
       `product_size_category` = '$size_category' 
  where clause..... (if required) ";