Row level security problem.

Question

Hy all, I'm new to Oracle and though i've google it a lot I didn't manage to find a solution to this problem:
I'm using sql developer and Oracle 10g.
I have this two tables :
CREATE TABLE HR_employees
(codHR NUMBER(3) CONSTRAINT pk_hr PRIMARY KEY,
coddep NUMBER(4) not null,
DB_user VARCHAR2(10),
and
CREATE TABLE Candid
(codcan NUMBER(2) CONSTRAINT PK_candidat PRIMARY KEY,
codHr NUMBER(3) NOT NULL,
CONSTRAINT FK_CODHR FOREIGN KEY (codHR) REFERENCES HR_employees (codHR) );
I tried to implement row level security on them by using two views:
CREATE OR REPLACE VIEW employees_v AS
SELECT * FROM hr_employees
WHERE DB_user = user
UNION
SELECT * FROM hr_employees
WHERE codhr=(SELECT codhr FROM hr_employees WHERE db_user=user );
AND coddep IN (4000,5000);
CREATE OR REPLACE VIEW candid_v AS
SELECT cand.*
FROM candid cand , hr_employees hr
WHERE cand.codhr= hr.codhr
AND hr.db_user=user
UNION
SELECT cand.* FROM candid cand, hr_employees hr
WHERE hr.coddep=(SELECT H.coddep FROM hr_employees H
WHERE H.db_user=user
AND H.coddep IN (4000,5000) );
What I want to do is to disconnect and connect with another user from SQL Developer and see different fields based on the user and the department, Sql developer doesn't seem to recognize the user connected to the database..everytime I receive a no row selected statement, only when I connect with SYS and put the actual username WHERE H.db_user='SYS' they seem to work. I have created the tables with SYS and granted Select on the views to the users, the users don't have privilegies on the actual tables.
Sorry for the bad english,it's a foreign language to me ,
I hope you can help me

Answer 1

Hi,
Damorgan is right: "Row level security has nothing to do with views" in the sense that the two are independent. You can have row-level security with or without views, and you can have views with or without row-level security. dbms_rls is a very useful and powerful way to implement row-level security, and you should check it out, but it's not necessarily the answer to all row-level security problems.
I'm not sure I understand your problem beyond the need to restrict user A's access to two tables.
If which rows user A is allowed to see depends on the results of queries from those same tables, including rows that user A is not allowed to see (that is, you need to do sub-queries with some other user's (let's call this user B's) privileges), then you can do those sub-queries in stored procedures.
Stored procuderes can run with the privileges of the procedure owner, regardless of who is calling them. Using a function called user_codhr owned by user B, you could define a view like this:
CREATE OR REPLACE VIEW employees_v AS
SELECT * FROM hr_employees
WHERE DB_user = user
OR    (   codhr = user_codhr
      AND coddep IN (4000,5000)
      );If the results of the function will be the same throughout the session, you can call it once, at the beginning of your session, and save the results in a SYS_CONTEXT varaible or a global temporary table.
If you need more help, post a more detailed example of the problem, such as "With this data in the table, B should see all rows but A should see only ...".