Min lösning har några rimliga krav, men jag kan arbeta utan den (priset är viss prestanda).
Jag byggde några hjälptabeller som är autofyllda med trigger. Kravet är att UPDATE
eller DELETE
är inte tillåtet vid besök bord.
mst_user tabell lagrar distinkt användar-id -s och det är första_besöket .user_monthly_visit tabellen lagrar det sista och första besöksdatumet pro user_id och månad .
TABELLER
CREATE TABLE mst_user (
id BIGINT,
first_visit TIMESTAMP,
CONSTRAINT pk_mst_user PRIMARY KEY (id)
);
CREATE TABLE visit (
user_id BIGINT,
visit_date TIMESTAMP,
CONSTRAINT visit_user_fkey FOREIGN KEY (user_id) REFERENCES mst_user (id)
);
CREATE TABLE user_monthly_visit (
user_id BIGINT,
month DATE,
first_visit_this_month TIMESTAMP,
last_visit_this_month TIMESTAMP,
CONSTRAINT pk_user_monthly_visit PRIMARY KEY (user_id, month),
CONSTRAINT user_monthly_visit_user_fkey FOREIGN KEY (user_id) REFERENCES mst_user (id)
);
CREATE INDEX ix_user_monthly_visit_month ON user_monthly_visit(month);
TRIGGER
CREATE OR REPLACE FUNCTION trf_visit() RETURNS trigger
VOLATILE
AS $xx$
DECLARE
l_user_id BIGINT;
l_row RECORD;
l_user_monthly_visit user_monthly_visit;
BEGIN
IF (tg_op = 'INSERT')
THEN
l_row := NEW;
INSERT INTO mst_user(id, first_visit) VALUES (l_row.user_id, l_row.visit_date)
ON CONFLICT(id) DO UPDATE SET first_visit = LEAST(mst_user.first_visit, l_row.visit_date);
INSERT INTO user_monthly_visit(user_id,month,first_visit_this_month,last_visit_this_month) VALUES (l_row.user_id,date_trunc('month',l_row.visit_date),l_row.visit_date,l_row.visit_date)
ON CONFLICT(user_id,month) DO UPDATE SET first_visit_this_month = LEAST(user_monthly_visit.first_visit_this_month,l_row.visit_date),
last_visit_this_month = GREATEST(user_monthly_visit.last_visit_this_month,l_row.visit_date);
ELSE
RAISE EXCEPTION 'UPDATE and DELETE arent allowed!';
END IF;
RETURN l_row;
END;
$xx$ LANGUAGE plpgsql;
CREATE TRIGGER trig_visit
BEFORE INSERT OR DELETE OR UPDATE ON visit
FOR EACH ROW
EXECUTE PROCEDURE trf_visit();
TESTDATA
INSERT INTO visit (user_id, visit_date)
VALUES (1, '20200101 122915');
INSERT INTO visit (user_id, visit_date)
VALUES (1, '20200102 123011');
INSERT INTO visit (user_id, visit_date)
VALUES (1, '20200401 123101');
INSERT INTO visit (user_id, visit_date)
VALUES (2, '20200501 123114');
FRÅGA
SELECT mnt AS month, user_id,
CASE WHEN first_visit IS NULL OR first_visit> yyyymm + INTERVAL '1 month' THEN NULL
WHEN first_visit_this_month = first_visit THEN 'FIRST'
WHEN first_visit_this_month IS NULL AND last_three_month + INTERVAL '3 month' >= yyyymm THEN 'RETENTION'
WHEN first_visit_this_month IS NOT NULL THEN 'REACTIVATE'
ELSE NULL
END user_type
FROM
(SELECT date_part('month', gs.yyyymm)::INTEGER AS mnt, gs.yyyymm, u.id user_id, umv.first_visit_this_month, umv.last_visit_this_month, u.first_visit,
GREATEST(
LAG(last_visit_this_month) OVER w,
LAG(last_visit_this_month,2) OVER w,
LAG(last_visit_this_month,3) OVER w
) last_three_month
FROM
generate_series('2020-01-01'::TIMESTAMP, '2020-12-01'::TIMESTAMP, INTERVAL '1 month') gs(yyyymm)
CROSS JOIN mst_user u
LEFT JOIN user_monthly_visit umv on (umv.user_id=u.id AND umv.month = gs.yyyymm)
WINDOW w AS (PARTITION BY u.id ORDER BY gs.yyyymm)
) monthly_visit
ORDER BY user_id,mnt;
RESULTAT
månad | user_id | användartyp |
---|---|---|
1 | 1 | FÖRST |
2 | 1 | RETENTION |
3 | 1 | RETENTION |
4 | 1 | ÅTERAKTIVERA |
5 | 1 | RETENTION |
6 | 1 | RETENTION |
7 | 1 | RETENTION |
8 | 1 | (null) |
9 | 1 | (null) |
10 | 1 | (null) |
11 | 1 | (null) |
12 | 1 | (null) |
1 | 2 | (null) |
2 | 2 | (null) |
3 | 2 | (null) |
4 | 2 | (null) |
5 | 2 | FÖRST |
6 | 2 | RETENTION |
7 | 2 | RETENTION |
8 | 2 | RETENTION |
9 | 2 | (null) |
10 | 2 | (null) |
11 | 2 | (null) |
12 | 2 | (null) |