来个SQL大神

[Usher丶AckMan]

[心随自在飞]

鄙人愚见：

select t1.*,'' as 'before-balance' from tab1 t1
union all
select t1.*,t2.banlance as 'before-balance' from tab1 t1,tab t2
where t1.no >1 and t1.no = t2.no-1 

[范海辛o]

[OPPPPOP]

用left_join就可以了 SELECT t.*, t1.balance before_balance FROM xx t LEFT JOIN xx t1 ON (t.no - 1 = t1.no AND t.pk = t1.pk) WHERE 1 = 1 ORDER BY t.no