MYSQL implements ranking and querying specified user ranking function (parallel ranking function) example code

CREATE TABLE test.testsort (
 
id int(11) NOT NULL AUTO_INCREMENT,
 
uid int(11) DEFAULT 0 COMMENT 'user id',
 
score decimal(10, 2) DEFAULT 0.00 COMMENT 'score',
 
PRIMARY KEY (id)
 
)
 
ENGINE = INNODB
 
AUTO_INCREMENT = 1
 
CHARACTER SET utf8
 
COLLATE utf8_general_ci
 
COMMENT = 'Test sorting'
 
ROW_FORMAT = DYNAMIC;

SELECT t.*, @rownum := @rownum + 1 AS rownum
 
FROM (SELECT @rownum := 0) r, (SELECT * FROM testsort ORDER BY score DESC) AS t;

SELECT t.*, @rownum := @rownum + 1 AS rownum
 
FROM (SELECT @rownum := 0) r, testsort AS t
 
ORDER BY t.score DESC;

SELECT b.* FROM
 
(
 
SELECT t.*, @rownum := @rownum + 1 AS rownum
 
FROM (SELECT @rownum := 0) r,
 
(SELECT * FROM testsort ORDER BY score DESC) AS t
 
) AS b WHERE b.uid = 222;

SELECT b.* from
 
(
 
SELECT t.*, @rownum := @rownum + 1 AS rownum
 
FROM (SELECT @rownum := 0) r, testsort AS t
 
ORDER BY t.score DESC
 
) as b where b.uid = 222;

SELECT
 
obj.uid,
 
obj.score,
 
CASE
 
WHEN @rowtotal = obj.score THEN
 
@rownum
 
WHEN @rowtotal := obj.score THEN
 
@rownum :=@rownum + 1
 
WHEN @rowtotal = 0 THEN
 
@rownum :=@rownum + 1
 
END AS rownum
 
FROM
 
(
 
SELECT
 
uid,
 
score
 
FROM
 
testsort
 
ORDER BY
 
score DESC
 
) AS obj,
 
(SELECT @rownum := 0 ,@rowtotal := NULL)

SELECT total.* FROM
 
(SELECT
 
obj.uid,
 
obj.score,
 
CASE
 
WHEN @rowtotal = obj.score THEN
 
@rownum
 
WHEN @rowtotal := obj.score THEN
 
@rownum :=@rownum + 1
 
WHEN @rowtotal = 0 THEN
 
@rownum :=@rownum + 1
 
END AS rownum
 
FROM
 
(
 
SELECT
 
uid,
 
score
 
FROM
 
testsort
 
ORDER BY
 
score DESC
 
) AS obj,
 
(SELECT @rownum := 0 ,@rowtotal := NULL) r) AS total WHERE total.uid = 222;