foreign key

Hi

is it a good practice to create FK on each & every column in a table whose values are taken from master table.

should I create or not.

If I create will that be heavy i.e what about memory consumption ?

pls reply

Thanks

Shubhangi1. You can foreign keys.

or

2. You can check through code. By using Inner join table name
on parenttabel.field=childtable.field

ro

3.Before inserting a record in child table, check whether it exists in the parent table through code by using if exists or if (select count(*) from tablename where
...)=0

or

if exists(select 1 from tablename where ...)