Zvažte následující:
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(fixture_id INT NOT NULL
,updated INT NOT NULL
,outcome ENUM('Home win','Draw','Away win') NOT NULL
,odds DECIMAL(5,2) NOT NULL
,PRIMARY KEY(fixture_id,outcome,updated)
);
INSERT INTO my_table VALUES
(120,12,'Home win',1.40),
(120,11,'Home win',1.10),
(120,10,'Home win',1.20),
(120,12,'Draw',1.50),
(120,11,'Draw',1.10),
(120,12,'Away win',1.30),
(120,11,'Away win',1.10),
(120,10,'Away win',1.60);
Poslední kurz:
SELECT x.*
FROM my_table x
JOIN
( SELECT fixture_id
, outcome
, MAX(updated) min_updated
FROM my_table x
GROUP
BY fixture_id
, outcome
) y
ON y.fixture_id = x.fixture_id
AND y.outcome = x.outcome
AND y.min_updated = x.updated;
Earliest odds:
Nejčasnější kurz:
SELECT x.*
FROM my_table x
JOIN
( SELECT fixture_id
, outcome
, MIN(updated) min_updated
FROM my_table x
GROUP
BY fixture_id
, outcome
) y
ON y.fixture_id = x.fixture_id
AND y.outcome = x.outcome
AND y.min_updated = x.updated;
Delta:
SELECT a.*
, a.odds - b.odds delta
FROM
( SELECT x.*
FROM my_table x
JOIN
( SELECT fixture_id
, outcome
, MAX(updated) min_updated
FROM my_table x
GROUP
BY fixture_id
, outcome
) y
ON y.fixture_id = x.fixture_id
AND y.outcome = x.outcome
AND y.min_updated = x.updated
) a
JOIN
( SELECT x.*
FROM my_table x
JOIN
( SELECT fixture_id
, outcome
, MIN(updated) min_updated
FROM my_table x
GROUP
BY fixture_id
, outcome
) y
ON y.fixture_id = x.fixture_id
AND y.outcome = x.outcome
AND y.min_updated = x.updated
) b
ON b.fixture_id = a.fixture_id
AND b.outcome = a.outcome;
Výsledek:
+------------+---------+----------+------+-------+
| fixture_id | updated | outcome | odds | delta |
+------------+---------+----------+------+-------+
| 120 | 12 | Home win | 1.40 | 0.20 |
| 120 | 12 | Draw | 1.50 | 0.40 |
| 120 | 12 | Away win | 1.30 | -0.30 |
+------------+---------+----------+------+-------+