db_next_id
function db_next_id
db_next_id($existing_id = 0)
Retrieves a unique id.
Use this function if for some reason you can't use a serial field. Using a serial field is preferred, and InsertQuery::execute() returns the value of the last ID inserted.
Parameters
$existing_id: After a database import, it might be that the sequences table is behind, so by passing in a minimum ID, it can be assured that we never issue the same ID.
Return value
An integer number larger than any number returned before for this sequence.