相關:
select 1,(select b2 from b where b1 = a1) from a
where a1 = 1;潛逃:
select 1,a2 from a
where a1 in (select b2 from b where b1 = 1);
select 1,(select b2 from b where b1 = a1) from a
where a1 = 1;潛逃:
select 1,a2 from a
where a1 in (select b2 from b where b1 = 1);
用文字说明呢?