從結果集中消除重復記錄
使用DISTINCT關鍵字即可從結果集中消除重復記錄。
SELECT
DATE_FORMAT( a.create_time, '%Y-%m-%d' ) AS create_date,
COUNT(*) orderCount,
COUNT(DISTINCT a.member_id) AS memberCount
FROM
convenience_order a
GROUP BY
DATE_FORMAT( a.create_time, '%Y-%m-%d' )
ORDER BY
DATE_FORMAT( a.create_time, '%Y-%m-%d' ) DESC
查詢結果
2022-06-20 4 2
2022-06-13 5 1
2022-06-10 2 1
2022-06-09 11 4
2022-06-08 14 5
2022-06-07 7 1
