Mysql程序自增变量

Question

我正在尝试使用存储时间获取表中的用户排名。

原始 SQL 查询工作正常，但我无法使其作为过程工作。

SET @rownum := 0;
SELECT rank, user_id, best_time
FROM (
  SELECT @rownum := @rownum +1 AS rank,id, best_time, user_id
  FROM user_round WHERE round_id=1 ORDER BY best_time ASC
) AS result WHERE user_id = 1 

我的尝试过程:

BEGIN
 DECLARE variable INT DEFAULT 0;
 SELECT rank,best_time, user_id
 FROM (
  SELECT SET variable=variable+1 AS rank, best_time, user_id
  FROM database.user_round WHERE round_id=1 ORDER BY best_time ASC
 ) AS result WHERE user_id = 1;
END

Answer 1

您需要继续使用 9.4. User-Defined Variables , 不是 13.6.4.1. Local Variable DECLARE Syntax :

BEGIN
    -- DECLARE variable INT DEFAULT 0;
    SELECT rank, best_time, user_id
    FROM (
        -- SELECT SET variable = variable + 1 AS rank, best_time, user_id
        SELECT @variable := @variable + 1 AS rank, best_time, user_id
        FROM database.user_round, (SELECT @variable := 0) init
        WHERE round_id = 1
        ORDER BY best_time ASC
    ) AS result
    WHERE user_id = 1;
END