Nīnau SQL e hoʻoholo i kahi papa inoa papa inoa08
14

I kēia lā ua ʻike wau i ka hana aʻe ma ka hana ʻana i kahi papahana mea kūʻai: E lawe i kahi pākaukau "SQL" me nā kolamu "id" a me "helu" a hoʻoholo i kahi papa inoa papa inoa o nā mea hoʻohana a pau i hoʻokaʻawale ʻia e ka "helu" i hoʻohana ʻia me nā e kiʻi i ka pae like me ka helu like. Hiki ke hoʻonā maʻalahi ʻia kēia hana ma o ka hoʻohana ʻana i nā loli i ho'ākāka ʻia e ka mea hoʻohana .

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CREATE TABLE
    user(id INT, score INT);
INSERT INTO
    user(id, score)
VALUES
    (1, 10), (2, 40), (3, 55), (4, 10), (5, 5), (6, 20), (7, 30), (8, 70), (9, 30)

Hoʻoholo maʻalahi ka hoʻohana ʻana i ʻelua mau loli i kēia

SET @score_prev = NULL;
SET @cur_rank = 0;
SELECT id, score, CASE
    WHEN @score_prev = score THEN @cur_rank
    WHEN @score_prev := score THEN @cur_rank := @cur_rank + 1
END AS rank
FROM user
ORDER BY score DESC

a loaʻa iā ʻoe ka hoʻopuka āu e makemake ai

+--------+-----------+----------+
|  *id*  |  *score*  |  *rank*  |
|    8   |      70   |      1   |
|    3   |      55   |      2   |
|    2   |      40   |      3   |
|    7   |      30   |      4   |
|    9   |      30   |      4   |
|    6   |      20   |      5   |
|    1   |      10   |      6   |
|    4   |      10   |      6   |
|    5   |       5   |      7   |
+--------+-----------+----------+