Search Postgresql Archives

Re: DB structure for logically similar objects in different

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



# eci.souji@xxxxxxxxx / 2006-05-29 08:10:43 -0400:
> Roman Neuhauser wrote:
> ># eci.souji@xxxxxxxxx / 2006-05-28 16:13:20 -0400:
> >
> >>Basically we've got several different "states" that an item can be in.
> >>From what I've seen the way many places seem to deal with them is
> >>something along the lines of making bool values that act as
> >>switches...
> >>
> >>Ex:
> >>table items:
> >>item_id
> >>name
> >>description
> >>is_active
> >>is_sold_out
> >>is_banned
> >>
> >>Now we've started to see some problems with this sort of design.
> >>Namely we need to run sanity tests on every page that hits the items
> >>table to make sure is_active is true, is_sold_out is false, is_banned
> >>is false so on and so forth.  I was thinking of splitting up states
> >>into different tables ala...
> >>
> >>table items_active:
> >>item_active_id
> >>name
> >>description
> >>
> >>table items_sold_out:
> >>item_sold_out_id
> >>name
> >>description
> >
> >
> >    would views help?
> >
> >    CREATE VIEW items_to_sell AS
> >     SELECT item_id, name, description
> >     FROM items
> >     WHERE is_active = 1 AND is_sold_out = 0 AND is_banned = 0;
> 
> Views work for querying the chunks of data that match different states, 
> but if I was looking for information based on a single item_id wouldn't 
> I still need the sanity checks?

    No.

    SELECT *
    FROM items_to_sell
    WHERE item_id = 123

    will be transformed into something like

    SELECT item_id, name, description
    FROM items
    WHERE item_id = 123
    AND is_active = 1
    AND is_sold_out = 0
    AND is_banned = 0

-- 
How many Vietnam vets does it take to screw in a light bulb?
You don't know, man.  You don't KNOW.
Cause you weren't THERE.             http://bash.org/?255991


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux