All,
Hello, I'm new to this list but I'm looking for some information.
What I need to do is to find a way to automallically insert a record if it
doesn'
t exist, prior to a SELECT.
Basically, I'm tracking some information based on date and the client
application when retrieving the information knows will that 'current' is
the record with today's date.
What I'd like is a way of of specifiying that when the SELECT is done,
there will be a check that a record exists for the current date and that if
it doesn't exist, a record will be inserted into the table for the current
date and then the SELECT will return the recors including the newly
inserted one.
What I've tried so far is a function that checks for the record, inserts it
if needed, and then returns a cursor that the client can use, but I was
wondering if there was something more direct. I thought of a RULE but I
don't see that they can do processing that expressive.
Here's an example: mytable contains the date based stats information with
another id. All the stats columns are defaulted so just inserting a new
record with the right id and date is sufficient.
=============
CREATE FUNCTION getdatestats (varchar) RETURNS refcursor AS '
DECLARE
myid ALIAS FOR $1;
today date;
ref refcursor;
dummyrow RECORD;
BEGIN
ref := 'statscursor';
SELECT INTO dummyrow * FROM mytable where id = AND statdate = today;
IF NOT FOUND
INSERT INTO mytable (id, statdate) VALUES (myid, today)
END IF;
OPEN ref for SELECT * FROM mytable WHERE id=myid;
RETURN ref;
END;
' LANGUAGE PLPGSQL
=============
Any other ideas? This works but I was wondering if it was possible to do
it without the client needing to do the transaction/cursor handling
(considering I'm only holding up to 30 days worth of data)
Thanks
Jay O'Connor
