这个语句怎么用not exists高效书写

newkid

〇〇 发表于 2016-12-21 08:26
left join + is null怎么写

不会吧，这么基础的东西？

with t as (select level+1 n from dual connect by level<=1e4/3)
,t2 as (
select a*n a,b*n b from p582,t where c*n<=1e4
)
select count(*) from (
select p.a,p.b from p582 p left join t2 on p.a=t2.a and p.b=t2.b
where t2.a is null
);

〇〇

原来是保留isnull的

qidan3500