I want to find the foreign keys of a table but there may be more than one user / schema with a table with the same name. How can I find the one that the currently logged user is seeing? Is there a function that gives its owner? What if there are public synonyms?
You can query the ALL_OBJECTS view:
select owner
, object_name
, object_type
from ALL_OBJECTS
where object_name = 'FOO'
To find synonyms:
select *
from ALL_SYNONYMS
where synonym_name = 'FOO'
Just to clarify, if a user references an object name with no schema qualification (e.g. 'FOO'), Oracle FIRST checks the user's schema for an object of that name (including synonyms in the user's schema. If it can't resolve the reference, Oracle then checks for a public synonym.
If you are looking specifically for constraints on a particular table_name:
select c.*
from all_constraints c
where c.table_name = 'FOO'
union all
select cs.*
from all_constraints cs
join all_synonyms s
on (s.table_name = cs.table_name
and s.table_owner = cs.owner
and s.synonym_name = 'FOO'
)
HTH
Interesting question - I don't think there's any Oracle function that does this (almost like a "which" command in Unix), but you can get the resolution order for the name by:
select * from
(
select object_name objname, object_type, 'my object' details, 1 resolveOrder
from user_objects
where object_type not like 'SYNONYM'
union all
select synonym_name obj , 'my synonym', table_owner||'.'||table_name, 2 resolveOrder
from user_synonyms
union all
select synonym_name obj , 'public synonym', table_owner||'.'||table_name, 3 resolveOrder
from all_synonyms where owner = 'PUBLIC'
)
where objname like upper('&objOfInterest')
Oracle views like ALL_TABLES and ALL_CONSTRAINTS have an owner column, which you can use to restrict your query. There are also variants of these tables beginning with USER instead of ALL, which only list objects which can be accessed by the current user.
One of these views should help to solve your problem. They always worked fine for me for similar problems.