Обсуждение: Re: [SQL] locked my keys in the car

At 9:10 AM 8/3/98, Thomas Good wrote:

>Next I tried Richard Lynch's suggestion:
>SELECT id FROM table
>WHERE office = 'M' AND (case = 'A' OR case = 'I')
>ORDER BY date DESC;
>
>And this is definitely on the right track as I am now down to
>75 patients (thanks Rich).
>
>The 13 active cases (in what we loosely term reality) are amongst
>the 75 returned tuples.  Moreover, I can catch the 62 inactive cases
>listed amongst the output from Rich's query with:
>
>SELECT tr_id, tr_date FROM crtrd1
>WHERE tr_unit = 'SMA' AND (tr_type = 'T' OR tr_type = 'O')
>ORDER BY tr_date DESC;
>
>(In this instance, T=terminated and O=outgoing...)
>
>So my next question is:
>Is there a way, using SQL, to do the math on this, i.e., to rm the
>patients who appear twice - once in the first query, once in the second?
>(God forbid we re-admit the same patient at some future date!)

Well I'm confused.  Nothing new there, eh?
If all you want is active cases, why not:

select id from table where office = 'M' and case = 'A' order by date desc;

>In other words, can I somehow go about rm'ing those patients who have
>a tr_type of T or O - with a tr_date that is > the tr_date of the entry
>with a tr_type of I or A?

You should be able to just mush all the stuff together in something like this

select distinct table.id from table, crtrd1 as entry, crtrd1 as exit where
    table.office = 'M' and (table.case = 'A' or table.case = 'I') and
    entry.tr_id = exit.tr_id and
    entry.tr_unit = 'SMA' and
    exit.tr_type != 'T' and exit..tr_type != 'O' and
    exit.tr_date > entry.tr_date and
    (entry.tr_type = 'A' or entry.tr_type = 'I');

I *THINK* this is kinda what you have asked for, but I don't really
understand for sure what your tables are, nor what you want to get out of
them...

--
--
-- "TANSTAAFL" Rich lynch@lscorp.com

Rich, Dave, Federico ---

Guys, for the assist!  The last piece of the puzzle follows.
A buddy of mine in Pennsylvania was able to force the date comparison.
Rich, this is pretty close to your code, a couple of minor diffs
do the job!

SELECT tr_id, tr_date
FROM crtrd1 ALIAS1
WHERE ALIAS1.tr_unit = 'SMA'
  AND (ALIAS1.tr_type = 'A' OR ALIAS1.tr_type = 'I')
  AND NOT EXISTS(
        SELECT tr_id
        FROM crtrd1 ALIAS2
        WHERE ALIAS2.tr_unit = 'SMA'
          AND ALIAS2.tr_id = ALIAS1.tr_id
          AND (ALIAS2.tr_type = 'T' OR ALIAS2.tr_type = 'O')
          AND ALIAS2.tr_date > ALIAS1.tr_date
  )
ORDER BY tr_date DESC;

Thanks for your assistance boys - I'm thinking of getting this
tattooed somewhere - somewhere I can see it when I need it that is!

    ---------- Sisters of Charity Medical Center ----------
                   Department of Psychiatry
                            ----
    Thomas Good                          <tomg@q8.nrnet.org>
    Coordinator, North Richmond C.M.H.C. Information Systems
    75 Vanderbilt Ave, Quarters 8        Phone: 718-354-5528
    Staten Island, NY   10304            Fax:   718-354-5056