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