update 表a set tel =
(case 地区 when '海淀' then '2'+tel
when '朝阳' then '3'+tel
when '崇文' then '4'+tel
when '宣武' then '5'+tel
...
end
)
(case 地区 when '海淀' then '2'+tel
when '朝阳' then '3'+tel
when '崇文' then '4'+tel
when '宣武' then '5'+tel
...
end
)
update customer set username='rose' where rownum>=100000 and rownum<200000;
老大你别拿我开心了,我是认真的~!!我写的那条语句后来是错的第一句:更新99999,第2句 更新0行select count(*) from t_testt_test
----------------
282800
while @@rowcount<>0
update customer set username='rose' where username<>'rose'