Hi All.

I want to select data from one table BUT only if there is a reference to it in another table.

Which is better example A or Example B ?

Table Not_want pkey, data. more_data

Table want_from pkey, data_needed, use_data

example A

Select wf.data_needed, wf.use_data
from not_want nw, want_from wf
where nw.pkey = wf.pkey
;

example B

Select data_needed
from want_from
where wf.pkey in ( Select pkey from not_want )
;


thank you