MySQL 5.7实现 row_number窗口函数

SELECT
pzrq,pzbh,pzlx,'example-1001','演示账套',id AS vou_id,subjcode,kmmc,zy,jfje,dfje,0,0,
if(@pzrq = pz.pzrq
AND @pzbh = pz.pzbh
and @pzlx = pz.pzlx,
@rank := @rank + 1,
@rank := 1
) AS rank_no,
@pzrq := pz.pzrq,
@pzbh := pz.pzbh,
@pzlx := pz.pzlx
FROM
pz,
( SELECT * FROM hs_subject WHERE account_code = 'example-1001' AND YEAR = '2017' ) b,
( SELECT @pzrq := null, @pzbh := null, @pzlx := null, @rank := 0 ) temp
WHERE
pz.kmmc = b.subjname