Moved to PGSQL, how to represent 'NEVER' with a timestamp

[simonk]

Hi all,

Having used MySQL 4 for a couple of years I've just moved to PostgreSQL for a new, larger project. It's early days but I must say I'm liking what I see, A LOT!

Anyway, I have a small but nagging question about timestamps. Specifically, I need some columns to be able to represent 'NEVER' as a special case. A typical example would be 'last_login_time' for a user. I'd like to be able to indicate that a user has not yet logged in.

For correctness I'm thinking that NULL is not appropriate as that implies missing or unknown data, which is not strictly the case. In MySQL I simply recorded a value of 0, but I'm a bit wary about PGSQL would make of this practice. What about using '-infinity'??

Any suggestions?

Thanks in advance!

sim

PS, anybody thinking of going PG, do it! It does all the things I wished I could do in MySQL (even v4).... nice!

[drawmack]

I've never used postgre but looking through their documentation at http://www.postgresql.org/docs/7.4/interactive/datatype-datetime.html#DATATYPE-DATETIME-INPUT is seems that you could default the timestamp field to some sort of epoch date maybe 1970-01-01 12:00 which then in your programming you can translate into never.

[simonk]

Thanks for your tip drawmack - that basically confirms what I had thought would be a reasonable solution - I'll give it a go!

cheers,

sim