Pull back rows from multiple tables with a sub-select? - sql

Question

I have a script which generates queries in the following fashion (based on user input):
SELECT * FROM articles
WHERE (articles.skeywords_auto ilike '%pm2%')
AND spubid IN (
SELECT people.spubid FROM people
WHERE (people.slast ilike 'chow')
GROUP BY people.spubid)
LIMIT 1;
The resulting data set:
Array ( [0] =>
Array (
[spubid] => A00603
[bactive] => t
[bbatch_import] => t
[bincomplete] => t
[scitation_vis] => I,X
[dentered] => 2009-07-24 17:07:27.241975
[sentered_by] => pubs_batchadd.php
[drev] => 2009-07-24 17:07:27.241975
[srev_by] => pubs_batchadd.php
[bpeer_reviewed] => t
[sarticle] => Errata: PM2.5 and PM10 concentrations from the Qalabotjha low-smoke fuels macro-scale experiment in South Africa (vol 69, pg 1, 2001)
[spublication] => Environmental Monitoring and Assessment
[ipublisher] =>
[svolume] => 71
[sissue] =>
[spage_start] => 207
[spage_end] => 210
[bon_cover] => f
[scover_location] =>
[scover_vis] => I,X
[sabstract] =>
[sabstract_vis] => I,X
[sarticle_url] =>
[sdoi] =>
[sfile_location] =>
[sfile_name] =>
[sfile_vis] => I
[sscience_codes] =>
[skeywords_manual] =>
[skeywords_auto] => 1,5,69,2001,africa,assessment,concentrations,environmental,errata,experiment,fuels,low-smoke,macro-scale,monitoring,pg,pm10,pm2,qalabotjha,south,vol
[saward_number] =>
[snotes] =>
)
The problem is that I also need all the columns from the 'people' table (as referenced in the sub select) to come back as part of the data set. I haven't (obviously) done much with sub selects in the past so this approach is very new to me. How do I pull back all the matching rows/columns from the articles table AS WELL as the rows/column from the people table?

Answer 1

Are you familiar with joins? Using ANSI syntax:
SELECT DISTINCT *
FROM ARTICLES t
JOIN PEOPLE p ON p.spubid = t.spudid AND p.slast ILIKE 'chow'
WHERE t.skeywords_auto ILIKE'%pm2%'
LIMIT 1;
The DISTINCT saves from having to define a GROUP BY for every column returned from both tables. I included it because you had the GROUP BY on your subquery; I don't know if it was actually necessary.

Answer 2

Could you not use a join instead of a sub-select in this case?
SELECT a.*, p.*
FROM articles as a
INNER JOIN people as p ON a.spubid = p.spubid
WHERE a.skeywords_auto ilike '%pm2%'
AND p.slast ilike 'chow'
LIMIT 1;

Answer 3

Lets start from the beginning
You shouldn't need a group by. Use distinct instead (you aren't doing any aggregating in the inner query).
To see the contents of the inner table, you actually have to join it. The contents are not exposed unless it shows up in the from section. A left outer join from the people table to the articles table should be equivalent to an IN query :
SELECT *
FROM people
LEFT OUTER JOIN articles ON articles.spubid = people.spubid
WHERE people.slast ilike 'chow'
AND articles.skeywords_auto ilike '%pm2%'
LIMIT 1