checking for duplicate entries

[Anon]

i currently have a script which creates new entries in a mysql database with a random ID number in the first field - generated from a rand() command.
is there an easy way to check for a duplicate ID number before inserting each new entry?

BoB.

[Anon]

In PHP:

$result=mysql_query('select id from mytable');
$ids=array();
while($id=mysql_fetch_row($result)) $ids[]=$id[0];
do
{...generate a random $id
}while(in_array($id,$ids);

$id is your unique random id.