Currently I have

PHP Code:

$sql = "REPLACE INTO $db_table(ID,URL,VALUE) VALUES ('$name','$url','$value') AND INSERT INTO $db_table('TIME') VALUES (NOW())";
if($result = mysql_query($sql ,$db)) {} else { echo ('Sorry we are currently experiancing technical problems.'); } 


But this is not working. Bascialy I want to overwrite some of the values using REPLACE but not others using INSERT

You will have to run two queries. Separate them with a semicolon

REPLACE ..... WHERE .... ;
INSERT INTO ...... ;

Im not too sure what you mean. Will that not create a separate row

A semicolon indicates the end of one command any commands after that are executed independently.

so the pseudocode I posted would run the replace first followed by the insert or is that NOT your intention?

No, I currently have 4 columns. ID, URL, VALUE, TIME. I want the code to update the VALUE if the ID already exists but insert the VALUE along with the ID URL and TIME if it does not exist.

Thanks, I am new to this stuff

You cannot do that in a single query, if your DB server supports stored procedures and passed parameters it would be posible to code a SP to handle the transactions.

otherwise your server side code will have to handle it

pseudocode:

SELECT id FROM table where id = [somevalue];

if id == null then
  [run insert]
else
   [run update]
end if

OK I see. What I am trying to work out is how http://whatsmytwitteraccountworth.com/ updates the 'top all time' value when a existing user is entered but does not update 'top today' or 'recent values', which I presume are calculated using the time the username is first posted posted

It probably updates the data, then requeries the database to display the new values.

sorted it using UPDATE