在group_concat中添加限制

Question

我的mysql查詢像：

SELECT GROUP_CONCAT(scorecard_id  ORDER BY scorecard_id DESC) as scorecard_id 
FROM scorecard 
WHERE partner_id = 121 AND client_id = 15

它向我返回如下數據：

65,64,63,62,61,60,39,38,37,36,35,34,33,32,31,30,29...

我想在group_concat中添加限制，以便它返回前兩個值，即：

65,64

Answer 1

也許用子查詢將其括起來：

SELECT 
GROUP_CONCAT(t.scorecard_id) AS scorecardId
FROM 
(
    SELECT
        scorecard_id
    FROM scorecard
    WHERE
        partner_id = 121
    AND client_id = 15
    ORDER BY scorecard_id DESC 
    LIMIT 2
) AS t;