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Re: Join query help

From: novice <user(dot)postgresql(at)gmail(dot)com>
To: pgsql-general(at)postgresql(dot)org, pgsql-sql(at)postgresql(dot)org
Cc: "Osvaldo Rosario Kussama" <osvaldo_kussama(at)yahoo(dot)com(dot)br>
Subject: Re: Join query help
Date: 2007-08-21 00:52:46
Message-ID: ddcb1c340708201752q15c61688t7e3f04387c6cdd38@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-generalpgsql-sql
Try 2: Here are my DDLs & DMLs

--  Start

CREATE TABLE record
(
  record_id integer PRIMARY KEY,
  record_date timestamp with time zone NOT NULL
);

INSERT INTO record(record_id, record_date) VALUES ('1', '2007-07-23 11:30:37');
INSERT INTO record(record_id, record_date) VALUES ('2', '2007-07-27 11:30:14');
INSERT INTO record(record_id, record_date) VALUES ('3', '2007-07-17 13:15:03');


CREATE TABLE score
(
  score_id integer PRIMARY KEY,
  score_description character(7) NOT NULL

);

INSERT INTO score(score_id, score_description) VALUES ('0', 'NA');
INSERT INTO score(score_id, score_description) VALUES ('1', 'SAFE');
INSERT INTO score(score_id, score_description) VALUES ('2', 'AT RISK');


CREATE TABLE observation
(
  observation_id integer PRIMARY KEY,
  record_id integer REFERENCES record (record_id),
  score_id integer REFERENCES score (score_id)
);

INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3240', '1', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3239', '1', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3238', '1', '2');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3237', '1', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('2872', '2', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('2869', '2', '2');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('2870', '2', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('2871', '2', '1');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3218', '3', '2');
INSERT INTO observation(observation_id, record_id, score_id) VALUES
('3217', '3', '1');

-- End

By executing

SELECT week,
COUNT(record) as records,
SUM(inspection) as inspections

  FROM
	(
	SELECT TO_CHAR(record.record_date, 'YYYY, WW') as week,	
	RECORD.RECORD_ID AS RECORD,
	COUNT(OBSERVATION_ID) AS INSPECTION
	  FROM OBSERVATION
	  LEFT JOIN record ON record.record_id = observation.record_id
	  GROUP BY RECORD, WEEK
         ) A

  GROUP BY WEEK;

I get

   week   | records | inspections
----------+---------+--------------
 2007, 30 |       2 |            8
 2007, 29 |       1 |            2
(2 rows)


I like to query for a result set that will also have the sum(score_id)
where score_id = '1' like the following

   week   | records | inspections | score
----------+---------+-------------+------
 2007, 30 |       2 |           8 |    6
 2007, 29 |       1 |           2 |    1
(2 rows)

This will help identify that there were 6 SAFE observations found from
the 8 inspections on week 30.

I hope this is not too confusing that I have to re-design the whole schema

In response to

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Subject: Re: Join query help
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