问如何通过另一列mysql查找相邻订单

EN

SELECT id, Student, score, 
FIND_IN_SET( score, (    
SELECT GROUP_CONCAT( score
ORDER BY score DESC ) 
FROM tbl )
) AS rank_in_class
FROM tbl
ORDER BY rank_in_class
LIMIT 3;

set @this_rank := (
                    SELECT
                          FIND_IN_SET( score, (    
                                                SELECT GROUP_CONCAT( score
                                                ORDER BY score DESC ) 
                                                FROM tbl 
                                                )
                                     ) AS rank_in_class
                    FROM tbl
                    where student = 'A'
                    );
select
*
from (
      SELECT
            id
          , Student
          , score
          , FIND_IN_SET( score, (    
                                  SELECT GROUP_CONCAT( score
                                  ORDER BY score DESC ) 
                                  FROM tbl 
                                  )
                       ) AS rank_in_class
      FROM tbl
     ) ric
where rank_in_class between @this_rank-1 AND @this_rank+1
ORDER BY rank_in_class
LIMIT 3;

$user = 'C'; // Student user we want to "focus"
$range = 1; // Range around the "focus" : 1 before and 1 after (could be changed to anything else)

// First query : retrieving the rank of the "focused" student
$stmt = $mysqli->prepare('SELECT COUNT(*) AS Rank FROM Student AS Focused INNER JOIN Student as Others ON Others.Score > Focused.Score OR (Others.Score = Focused.Score AND Others.Id > Focused.Id) WHERE Focused.user = ?');
$stmt->bind_param('s',$user);
$stmt->execute();
$res = $stmt->get_result()->fetch_assoc();
$startRank = $res['Rank'];

// Computing the dynamic LIMIT
if (($startRank - $range) < 1) {
  $offset = 0;
  $rowCount = $startRank + $range + 1;
} else {
  $offset = $startRank - $range;
  $rowCount = ($range * 2)+1;
}

// Second query : retrieving the rank of all the students around the "focused" student
$stmt = $mysqli->prepare('SELECT id, user, score, @curRank := @curRank + 1 AS rank FROM Student, (SELECT @curRank := ?) Rank ORDER BY Score DESC, id DESC LIMIT ?, ?');
$stmt->bind_param('iii',$offset,$offset,$rowCount);
$stmt->execute();