计算同比

SELECT
    old.now_time,
    ROUND( ( new.count - old.count ) / old.count * 100, 2 ),
    new.count ncount,
    old.count ocount 
FROM (
SELECT
    sum( IF ( b.count > 1, 1, 1 ) ) count,
    b.now_time,
    b.tenant_code 
FROM
    (
    SELECT
        date_format( ro.create_dt, '%Y-%m' ) AS now_time,
        a.tenant_code,
        a.order_no,
        count( a.id ) count 
    FROM
        t_rep_order_timeout a 
    INNER JOIN t_rep_order ro on 
        a.tenant_code = ro.tenant_code and a.order_no = ro.order_no
    WHERE
        a.tenant_code = 'zlyy' 
    GROUP BY
        date_format( ro.create_dt, '%Y-%m' ),
        a.tenant_code,
        a.order_no 
    ) b 
GROUP BY
    b.now_time,
    b.tenant_code
    ) new 
LEFT JOIN
(SELECT
    sum( IF ( b.count > 1, 1, 1 ) ) count,
    b.now_time,
    b.tenant_code 
FROM
    (
    SELECT
        date_format( DATE_ADD( ro.create_dt, INTERVAL 1 YEAR ), '%Y-%m') AS now_time,
        a.tenant_code,
        a.order_no,
        count( a.id ) count 
    FROM
        t_rep_order_timeout a 
    INNER JOIN t_rep_order ro on 
        a.tenant_code = ro.tenant_code and a.order_no = ro.order_no
    WHERE
        a.tenant_code = 'zlyy' 
    GROUP BY
        date_format( DATE_ADD( ro.create_dt, INTERVAL 1 YEAR ), '%Y-%m'),
        a.tenant_code,
        a.order_no 
    ) b 
GROUP BY
    b.now_time,
    b.tenant_code) old 
    on old.tenant_code = new.tenant_code and old.now_time = new.now_time

计算环比

SELECT
    old.now_time,
    ROUND( ( new.count - old.count ) / old.count * 100, 2 ),
    new.count ncount,
    old.count ocount 
FROM (
SELECT
    sum( IF ( b.count > 1, 1, 1 ) ) count,
    b.now_time,
    b.tenant_code 
FROM
    (
    SELECT
        date_format( ro.create_dt, '%Y-%m' ) AS now_time,
        a.tenant_code,
        a.order_no,
        count( a.id ) count 
    FROM
        t_rep_order_timeout a 
    INNER JOIN t_rep_order ro on 
        a.tenant_code = ro.tenant_code and a.order_no = ro.order_no
    WHERE
        a.tenant_code = 'zlyy' 
    GROUP BY
        date_format( ro.create_dt, '%Y-%m' ),
        a.tenant_code,
        a.order_no 
    ) b 
GROUP BY
    b.now_time,
    b.tenant_code
    ) new 
LEFT JOIN
(SELECT
    sum( IF ( b.count > 1, 1, 1 ) ) count,
    b.now_time,
    b.tenant_code 
FROM
    (
    SELECT
        date_format( DATE_ADD( ro.create_dt, INTERVAL 1 MONTH ), '%Y-%m') AS now_time,
        a.tenant_code,
        a.order_no,
        count( a.id ) count 
    FROM
        t_rep_order_timeout a 
    INNER JOIN t_rep_order ro on 
        a.tenant_code = ro.tenant_code and a.order_no = ro.order_no
    WHERE
        a.tenant_code = 'zlyy' 
    GROUP BY
        date_format( DATE_ADD( ro.create_dt, INTERVAL 1 MONTH ), '%Y-%m'),
        a.tenant_code,
        a.order_no 
    ) b 
GROUP BY
    b.now_time,
    b.tenant_code) old 
    on old.tenant_code = new.tenant_code and old.now_time = new.now_time

获取某一年份所有月份

SELECT
CASE
        
    WHEN
        length( mon ) = 1 THEN
            concat( '2019-0', mon ) ELSE concat( '2019-', mon ) 
        END months 
FROM
    ( SELECT @m := @m + 1 mon FROM t_rep_order_timeout, ( SELECT @m := 0 ) a ) aa 
    LIMIT 12

此处所用的辅助表t_rep_oder_timeot表数据必须超过12条

删除表内的重复数据

DELETE t 
FROM
    interview t
    LEFT JOIN ( SELECT title, min( id ) AS min_id FROM interview GROUP BY title ) t1 ON t.id = t1.min_id 
WHERE
    t1.min_id IS NULL;