SQL实现累计当前年份（行）的数量（列）

Posted 2021-08-29 被雨遗忘的夏天

数据结构图

 

期望结构图

实现代码 

SELECT
    t.years,
    t.manufacturer,
    t.object_name,
    t.year_count,
    @running_total:=@running_total + t.year_count AS cum_year_count
FROM
    (SELECT
        SUBSTRING_INDEX(plant_transfer_date, '-', 1) AS years,
            manufacturer,
            object_name,
            COUNT(1) AS year_count
    FROM
        scxt_dm_rp_main_device
    WHERE
        manufacturer = 'A'
    GROUP BY object_name , manufacturer , years) t
        JOIN
    (SELECT @running_total:=0) r
ORDER BY t.years;