select id from (select id from testtable order by id asc) t where not exists (select 1 from testtable where id=t.id-1)
mysql的in和exists
in适合于外表大而内表小的情况,exists适合于外表小而内表大的情况。
select id from (select id from testtable order by id asc) t where not exists (select 1 from testtable where id=t.id-1)
in适合于外表大而内表小的情况,exists适合于外表小而内表大的情况。