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--
-- WINDOW FUNCTIONS
--
CREATE TEMPORARY TABLE empsalary (
depname varchar,
empno bigint,
salary int,
enroll_date date
);
INSERT INTO empsalary VALUES
('develop', 10, 5200, '2007-08-01'),
('sales', 1, 5000, '2006-10-01'),
('personnel', 5, 3500, '2007-12-10'),
('sales', 4, 4800, '2007-08-08'),
('personnel', 2, 3900, '2006-12-23'),
('develop', 7, 4200, '2008-01-01'),
('develop', 9, 4500, '2008-01-01'),
('sales', 3, 4800, '2007-08-01'),
('develop', 8, 6000, '2006-10-01'),
('develop', 11, 5200, '2007-08-15');
SELECT depname, empno, salary, sum(salary) OVER (PARTITION BY depname) FROM empsalary ORDER BY depname, salary;
SELECT depname, empno, salary, rank() OVER (PARTITION BY depname ORDER BY salary) FROM empsalary;
-- with GROUP BY
SELECT four, ten, SUM(SUM(four)) OVER (PARTITION BY four), AVG(ten) FROM tenk1
GROUP BY four, ten ORDER BY four, ten;
SELECT depname, empno, salary, sum(salary) OVER w FROM empsalary WINDOW w AS (PARTITION BY depname);
SELECT depname, empno, salary, rank() OVER w FROM empsalary WINDOW w AS (PARTITION BY depname ORDER BY salary) ORDER BY rank() OVER w;
-- empty window specification
SELECT COUNT(*) OVER () FROM tenk1 WHERE unique2 < 10;
SELECT COUNT(*) OVER w FROM tenk1 WHERE unique2 < 10 WINDOW w AS ();
-- no window operation
SELECT four FROM tenk1 WHERE FALSE WINDOW w AS (PARTITION BY ten);
-- cumulative aggregate
SELECT sum(four) OVER (PARTITION BY ten ORDER BY unique2) AS sum_1, ten, four FROM tenk1 WHERE unique2 < 10;
SELECT row_number() OVER (ORDER BY unique2) FROM tenk1 WHERE unique2 < 10;
SELECT rank() OVER (PARTITION BY four ORDER BY ten) AS rank_1, ten, four FROM tenk1 WHERE unique2 < 10;
SELECT dense_rank() OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT percent_rank() OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT cume_dist() OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT ntile(3) OVER (ORDER BY ten, four), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT ntile(NULL) OVER (ORDER BY ten, four), ten, four FROM tenk1 LIMIT 2;
SELECT lag(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lag(ten, four) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lag(ten, four, 0) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten * 2, 1) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten * 2, 1, -1) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT first_value(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
-- last_value returns the last row of the frame, which is CURRENT ROW in ORDER BY window.
SELECT last_value(four) OVER (ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT last_value(ten) OVER (PARTITION BY four), ten, four FROM
(SELECT * FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten)s
ORDER BY four, ten;
SELECT nth_value(ten, four + 1) OVER (PARTITION BY four), ten, four
FROM (SELECT * FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten)s;
SELECT ten, two, sum(hundred) AS gsum, sum(sum(hundred)) OVER (PARTITION BY two ORDER BY ten) AS wsum
FROM tenk1 GROUP BY ten, two;
SELECT count(*) OVER (PARTITION BY four), four FROM (SELECT * FROM tenk1 WHERE two = 1)s WHERE unique2 < 10;
SELECT (count(*) OVER (PARTITION BY four ORDER BY ten) +
sum(hundred) OVER (PARTITION BY four ORDER BY ten))::varchar AS cntsum
FROM tenk1 WHERE unique2 < 10;
-- opexpr with different windows evaluation.
SELECT * FROM(
SELECT count(*) OVER (PARTITION BY four ORDER BY ten) +
sum(hundred) OVER (PARTITION BY two ORDER BY ten) AS total,
count(*) OVER (PARTITION BY four ORDER BY ten) AS fourcount,
sum(hundred) OVER (PARTITION BY two ORDER BY ten) AS twosum
FROM tenk1
)sub
WHERE total <> fourcount + twosum;
SELECT avg(four) OVER (PARTITION BY four ORDER BY thousand / 100) FROM tenk1 WHERE unique2 < 10;
SELECT ten, two, sum(hundred) AS gsum, sum(sum(hundred)) OVER win AS wsum
FROM tenk1 GROUP BY ten, two WINDOW win AS (PARTITION BY two ORDER BY ten);
-- more than one window with GROUP BY
SELECT sum(salary),
row_number() OVER (ORDER BY depname),
sum(sum(salary)) OVER (ORDER BY depname DESC)
FROM empsalary GROUP BY depname;
-- identical windows with different names
SELECT sum(salary) OVER w1, count(*) OVER w2
FROM empsalary WINDOW w1 AS (ORDER BY salary), w2 AS (ORDER BY salary);
-- subplan
SELECT lead(ten, (SELECT two FROM tenk1 WHERE s.unique2 = unique2)) OVER (PARTITION BY four ORDER BY ten)
FROM tenk1 s WHERE unique2 < 10;
-- empty table
SELECT count(*) OVER (PARTITION BY four) FROM (SELECT * FROM tenk1 WHERE FALSE)s;
-- mixture of agg/wfunc in the same window
SELECT sum(salary) OVER w, rank() OVER w FROM empsalary WINDOW w AS (PARTITION BY depname ORDER BY salary DESC);
-- strict aggs
SELECT empno, depname, salary, bonus, depadj, MIN(bonus) OVER (ORDER BY empno), MAX(depadj) OVER () FROM(
SELECT *,
CASE WHEN enroll_date < '2008-01-01' THEN 2008 - extract(YEAR FROM enroll_date) END * 500 AS bonus,
CASE WHEN
AVG(salary) OVER (PARTITION BY depname) < salary
THEN 200 END AS depadj FROM empsalary
)s;
-- test non-default frame specifications
SELECT four, ten,
sum(ten) over (partition by four order by ten),
last_value(ten) over (partition by four order by ten)
FROM (select distinct ten, four from tenk1) ss;
SELECT four, ten,
sum(ten) over (partition by four order by ten range between unbounded preceding and current row),
last_value(ten) over (partition by four order by ten range between unbounded preceding and current row)
FROM (select distinct ten, four from tenk1) ss;
SELECT four, ten,
sum(ten) over (partition by four order by ten range between unbounded preceding and unbounded following),
last_value(ten) over (partition by four order by ten range between unbounded preceding and unbounded following)
FROM (select distinct ten, four from tenk1) ss;
SELECT four, ten/4 as two,
sum(ten/4) over (partition by four order by ten/4 range between unbounded preceding and current row),
last_value(ten/4) over (partition by four order by ten/4 range between unbounded preceding and current row)
FROM (select distinct ten, four from tenk1) ss;
SELECT four, ten/4 as two,
sum(ten/4) over (partition by four order by ten/4 rows between unbounded preceding and current row),
last_value(ten/4) over (partition by four order by ten/4 rows between unbounded preceding and current row)
FROM (select distinct ten, four from tenk1) ss;
-- with UNION
SELECT count(*) OVER (PARTITION BY four) FROM (SELECT * FROM tenk1 UNION ALL SELECT * FROM tenk2)s LIMIT 0;
-- ordering by a non-integer constant is allowed
SELECT rank() OVER (ORDER BY length('abc'));
-- but this draws an error: "ORDER BY 1" means order by first SELECT column
SELECT rank() OVER (ORDER BY 1);
-- some other errors
SELECT * FROM empsalary WHERE row_number() OVER (ORDER BY salary) < 10;
SELECT * FROM empsalary INNER JOIN tenk1 ON row_number() OVER (ORDER BY salary) < 10;
SELECT rank() OVER (ORDER BY 1), count(*) FROM empsalary GROUP BY 1;
SELECT * FROM rank() OVER (ORDER BY random());
DELETE FROM empsalary WHERE (rank() OVER (ORDER BY random())) > 10;
DELETE FROM empsalary RETURNING rank() OVER (ORDER BY random());
SELECT count(*) OVER w FROM tenk1 WINDOW w AS (ORDER BY unique1), w AS (ORDER BY unique1);
SELECT rank() OVER (PARTITION BY four, ORDER BY ten) FROM tenk1;
SELECT count() OVER () FROM tenk1;
SELECT generate_series(1, 100) OVER () FROM empsalary;
SELECT ntile(0) OVER (ORDER BY ten), ten, four FROM tenk1;
SELECT nth_value(four, 0) OVER (ORDER BY ten), ten, four FROM tenk1;
-- cleanup
DROP TABLE empsalary;
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