How can I get the foreign key and packages info?

I can get the table info from sys.user_tables.get the column info from sys.er_tab_columns.Now I want get foreign key info ,and package info.which view can provide this info?
please help.

You can check user_constraints view for Primary and Foreign keys. There is a field called Constraint_Type, which shows whether it is Primary(P) or Foreign(R) key.

If you want a list of columns in primary or foreign key, then refer to user_cons_columns view.

For package source refer to user_source view.

thanks very much