update column based on the sort order of another query
Let's start with a table, put data in it, add a sort order column

USE test
DROP TABLE IF EXISTS ordered_names;
CREATE TABLE ordered_names
(
    id int not null auto_increment,
    firstname VARCHAR(20),
    lastname VARCHAR(20),
    PRIMARY KEY (id),
    KEY name_ndx (lastname,firstname)
);
INSERT INTO ordered_names (firstname,lastname) VALUES
('pamela','edwards'),('rolando','edwards'),('diamond','edwards');
ALTER TABLE ordered_names ADD COLUMN sort_order INT DEFAULT NULL;
SELECT * FROM ordered_names;


Let's actually run that:

mysql&gt; USE test
Database changed
mysql&gt; DROP TABLE IF EXISTS ordered_names;
Query OK, 0 rows affected (0.00 sec)

mysql&gt; CREATE TABLE ordered_names
    -&gt; (
    -&gt;     id int not null auto_increment,
    -&gt;     firstname VARCHAR(20),
    -&gt;     lastname VARCHAR(20),
    -&gt;     PRIMARY KEY (id),
    -&gt;     KEY name_ndx (lastname,firstname)
    -&gt; );
Query OK, 0 rows affected (0.04 sec)

mysql&gt; INSERT INTO ordered_names (firstname,lastname) VALUES
    -&gt; ('pamela','edwards'),('rolando','edwards'),('diamond','edwards');
Query OK, 3 rows affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql&gt; ALTER TABLE ordered_names ADD COLUMN sort_order INT DEFAULT NULL;
Query OK, 3 rows affected (0.17 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql&gt; SELECT * FROM ordered_names;
+----+-----------+----------+------------+
| id | firstname | lastname | sort_order |
+----+-----------+----------+------------+
|  1 | pamela    | edwards  |       NULL |
|  2 | rolando   | edwards  |       NULL |
|  3 | diamond   | edwards  |       NULL |
+----+-----------+----------+------------+
3 rows in set (0.00 sec)

mysql&gt;


Next, let's populate the sort order column:

SET @x = 0;
UPDATE ordered_names SET sort_order = (@x:=@x+1) ORDER BY lastname,firstname;
SELECT * FROM ordered_names;


Let's run that:

mysql&gt; SET @x = 0;
Query OK, 0 rows affected (0.00 sec)

mysql&gt; UPDATE ordered_names SET sort_order = (@x:=@x+1) ORDER BY lastname,firstname;
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql&gt; SELECT * FROM ordered_names;
+----+-----------+----------+------------+
| id | firstname | lastname | sort_order |
+----+-----------+----------+------------+
|  1 | pamela    | edwards  |          2 |
|  2 | rolando   | edwards  |          3 |
|  3 | diamond   | edwards  |          1 |
+----+-----------+----------+------------+
3 rows in set (0.00 sec)

mysql&gt;


OK, good so far, let's add four(4) more people and reorder:

INSERT INTO ordered_names (firstname,lastname) VALUES
('javonne','washington'),('richard','washington'),
('carlik','washington'),('dominique','edwards');
SET @x = 0;
UPDATE ordered_names SET sort_order = (@x:=@x+1) ORDER BY lastname,firstname;
SELECT * FROM ordered_names;


Let's run that:

mysql&gt; INSERT INTO ordered_names (firstname,lastname) VALUES
    -&gt; ('javonne','washington'),('richard','washington'),
    -&gt; ('carlik','washington'),('dominique','edwards');
Query OK, 4 rows affected (0.00 sec)
Records: 4  Duplicates: 0  Warnings: 0

mysql&gt; SET @x = 0;
Query OK, 0 rows affected (0.00 sec)

mysql&gt; UPDATE ordered_names SET sort_order = (@x:=@x+1) ORDER BY lastname,firstname;
Query OK, 6 rows affected (0.00 sec)
Rows matched: 7  Changed: 6  Warnings: 0

mysql&gt; SELECT * FROM ordered_names;
+----+-----------+------------+------------+
| id | firstname | lastname   | sort_order |
+----+-----------+------------+------------+
|  1 | pamela    | edwards    |          3 |
|  2 | rolando   | edwards    |          4 |
|  3 | diamond   | edwards    |          1 |
|  4 | javonne   | washington |          6 |
|  5 | richard   | washington |          7 |
|  6 | carlik    | washington |          5 |
|  7 | dominique | edwards    |          2 |
+----+-----------+------------+------------+
7 rows in set (0.00 sec)

mysql&gt;


Give it a Try !!!