Hi.
On Sat 2002-12-28 at 08:15:58 -0500, [EMAIL PROTECTED] wrote:
[...]
> create table schedule
> (
> # ID number
> id smallint not null default 0 auto_increment primary key ,
> client smallint , # references client.id
> class smallint , # references classtypes.id
> place smallint , # references places.id
> instr smallint , # references personnel.id
> time datetime # when
Don't you need some kind of duration? Or are the times fixed and you
know beforehand when the class starting at x o'clock will end? And
saving a number for the time slot would also work?
> ) ;
>
> I could, for every insert, check
>
> select * from schedule where client = '1' and time = '...' ;
>
> to make sure the client isn't being booked twice, or
>
> select * from schedule where instr = '1' and time = '...' ;
>
> to make sure the instructor isn't double-booked, but
In the case of time slots, you could create a unique index on
(client,time) and (instr,time) and skip the selects. Simply insert and
check for an duplicate key error.
> that seems like it would get awfully slow as the table grows...
I wonder why you think so. Maybe I do not understand your concern
correctly, but with the right indexes this shouldn't be slow. Do I
miss something?
If not: Whether an index (client,time) or (time,client) is better
depends on your data (few or a lot of client, etc). If you don't have
time slots, even (client) or (time) would help, although not as much.
I you are not sure, simply build all of them and look which one get
used. Then dropped the other ones again. The same applies for "instr".
> Is this the sort of thing where a temporary table is advised, or
> should I define a reverse table that shows each instructor and
> his/her bookings, or what?
I am not sure how a temporary table would improve things. So we have
some kind of misunderstanding. Could you post how you would use
temporary tables here? Then I could easier tell, how I would do the
same.
HTH,
Benjamin.
--
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