Hello,
Say for example that you have a table called 'user' that has a couple columns called "userid, username, passwd, notes, eyecolor, etc".
You use the following SQL query to find a userid (a #) with the username of 'justin';
SELECT userid, username FROM user WHERE username = 'justin';
in the example this will return userid "51". You will them create a query something like this.
UPDATE user SET username = 'justin', passwd = 'testing', notes = 'some notes', eyecolor = 'brown', etc = 'other stuff' WHERE userid = 51;
so we just took the userid 51 and created a update statement using SQL so that they can change their settings.
Hope this helps,
- Justin