mysql - SQL request using left join -

i have 2 tables.

table : (id, type, ...)
here id primary key

table b : (id, timestamp, old_type, new_type, ...)
here id not primary key

i want make sql request return such ids each a.type not same last (by timestamp) b.new_type.

is helpful nikita?

select a.* a a.type!= (      select b.new_type b b order `timestamp` desc limit 1 )

Camp