I have restricted select access at table level for 1 single table 'A'in sql server(2016).
But users are able to access views which are created top of that table 'A'.
when users run select statement on table 'A'(select * from table 'A')users are getting 'select permission is denied on object table 'A' ' message.
when users run select statement on view (select * from view 'A') users are able to access all data.
Users are able to create new views by writing select statement on table 'A'.
How can i restrict users to access table 'A' from views as well.
This is expected behavior due to ownership chaining. Permissions on tables referenced by the view are not checked as long as the view and tables have the same owner (AUTHORIZATION).
To break the ownership chain, you could either move the table to a different schema (owned by a different user than the view schema) or change to owner of the table. Examples below.
--move table to different schema
CREATE USER RestricedTablesOwner WITHOUT LOGIN;
GO
CREATE SCHEMA RestricedTables AUTHORIZATION RestricedTablesOwner;
GO
ALTER SCHEMA RestricedTables TRANSFER dbo.A;
GO
--change table to different owner, retaining same schema
ALTER AUTHORIZATION ON OBJECT::dbo.A TO RestricedTablesOwner;
Related
I have created a table 'T' under user 'SYS'. Now I want to view the contents of the same table 'T' under another user 'JACH'. I have granted the select privileges' on table 'T' to user 'JACH'. But when I try to view the table under 'JACH', it says table doesn't exist. How do I view the table data under user 'JACH'?[Logged in as user 'SYS']
[Logged in as user 'JACH']
You need to schema qualify your select statement.
If a table is created under SCHEMA1 and you wish to query it while connected to SCHEMA2, assuming that SCHEMA2 has been granted SELECT/READ privileges properly, you should be able to query the table while connected to SCHEMA2 like this:
SELECT * FROM SCHEMA1.TABLE_NAME;
Users have create table statement with select statement from multiple tables from multiple schema. I want to restrict them to read data and allow them to create empty table in their schema with metadata only not data. This I want to do at user access and roles level.
Please tell me how I can do this?
I have tried giving them read access on underlying tables but users can see data as well.
Create table cust_acct_details
as
select *
from ep_rel.acct a
inner join ep_dnf.Cust_account ca
on a.acct_id = ca.acct_id
Tables should create without data.
Add below condition to your code
-- condition to add where 1<>1
Create table cust_acct_details
as
select *
from ep_rel.acct a
inner join ep_dnf.Cust_account ca
on a.acct_id = ca.acct_id
where 1<>1
Please make sure there are unique column names in your select statement. Oracle will not allow same column name in one table. Please use alias instead of *.
If you remove all tablespace privileges from a user they can still create tables but they won't be able to populate them.
For example, if you run this PL/SQL block to revoke all tablespace quotas from one user:
begin
for users in
(
select 'alter user '||username||' quota 0 on '||tablespace_name v_sql
from dba_ts_quotas
where username = 'TEST_USER'
order by 1
) loop
execute immediate users.v_sql;
end loop;
end;
/
Now the user can create tables but will get an error if they try to add rows:
SQL> create table test1(a number);
Table created.
SQL> insert into test1 values(1);
insert into test1 values(1)
*
ERROR at line 1:
ORA-01536: space quota exceeded for tablespace 'USERS'
For metadata, users can always see the metadata in their own schema. To allow them to view the metadata in other schema, run a grant like:
grant select_catalog_role to the_user;
Then that user can view the metadata either in the ALL_ data dictionary views, or using DBMS_METADATA.GET_DDL.
What is the query to get a list of schemas names in a specific database in Informix?
Schemas are not commonly used in Informix databases and have very little trackability within a database. The CREATE SCHEMA notation is supported because it was part of SQL-89. The AUTHORIZATION clause is used to determine the (default) 'owner' of the objects created with the CREATE SCHEMA statement. There is nothing to stop a single user running the CREATE SCHEMA statement multiple times, either consecutively or at widely different times (in any given database within an Informix instance).
CREATE SCHEMA AUTHORIZATION "pokemon"
CREATE TABLE gizmo (s SERIAL NOT NULL PRIMARY KEY, v VARCHAR(20) NOT NULL)
CREATE TABLE widget(t SERIAL NOT NULL PRIMARY KEY, d DATETIME YEAR TO SECOND NOT NULL)
;
CREATE SCHEMA AUTHORIZATION "pokemon"
CREATE TABLE object (u SERIAL NOT NULL PRIMARY KEY, i INTEGER NOT NULL)
CREATE TABLE "pikachu".complain (C SERIAL NOT NULL PRIMARY KEY, v VARCHAR(255) NOT NULL)
;
After the CREATE SCHEMA statement executes, there is no way of tracking that either pair of these tables were created together as part of the same schema; there's no way to know that "pikachu".complain was part of a CREATE SCHEMA statement executed on behalf of "pokemon". There is no DROP SCHEMA statement that would necessitate such support.
A schema belongs to a user. You can list all available users from the sysusers system catalog :
SELECT username FROM "informix".sysusers;
Since only DBAs and Resource privilieges allow a user to issue a CREATE SCHEMA statement, we could restrict the query like :
SELECT username FROM "informix".sysusers WHERE usertype IN ('D', 'R');
Another solution is to list only users that actually have created tables ; for that, you can query the systables system catalog and list distinct owners.
SELECT DISTINCT owner FROM FROM "informix".systables
As commented by #JonathanLeffler, a user could have been granted RESOURCE privileges and have created a table, and then be 'demoted' to CONNECT privileges. The user would still own the table. Hence the second solution is the most accurate.
I just created two tables and they are named as tblA and tblB. I also created a user(Security/Login) who will be used for a remote insert/update.
What is the best way to permit this user to access for only those two table out of 50 table. I have tried look for the way from (Security/Login) and (Database/Properties). Can I limit it from user account level?
Use a 'grant' statement:
grant select on tblA to the_user_name
grant insert on tblA to the_user_name
grant update on tblA to the_user_name
Goal: When everybody else does SELECT * FROM mytable they see one version of the table. But when a specific user does SELECT * FROM mytable they see another version of the table.
I think I'm like halfway there with creating a new role and putting the single user in it. Then creating a copy of the default table with SELECT * INTO newrole.mytable FROM dbo.mytable. But when the user does SELECT * FROM mytable they still see the dbo.mytable. How do I get them to default to the newrole.mytable? I still need them to see all the other dbo tables just not this one.
Create a new schema, and a duplicate table (or view onto dbo.table if that's what you want) in it - eg., otheruser.table. Then, set the user's login to default to that schema:
USE atest
GO
CREATE ROLE [arole]
GO
CREATE SCHEMA [aschema] AUTHORIZATION [arole]
GO
CREATE USER [auser] FOR LOGIN [modify_user] WITH DEFAULT_SCHEMA = aschema
GO
EXEC sp_addrolemember 'arole', 'auser'
GO
CREATE TABLE dbo.atable ( col1 int )
GO
CREATE TABLE aschema.atable (col2 varchar(10))
GO
INSERT INTO dbo.atable( col1 ) VALUES( 1 )
GO
INSERT INTO aschema.atable( col2 ) VALUES( 'One' )
GO
PRINT 'dbo'
SELECT * FROM atable
GO
EXECUTE AS USER = 'auser'
GO
PRINT 'aschema'
SELECT * FROM atable
GO
REVERT
GO
I don't know if this may help but you may be able to make a view of a different table with the same name, here is an excerpt from http://www.w3schools.com/SQl/sql_view.asp:
In SQL, a view is a virtual table based on the result-set of an SQL statement.
A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database.
You can add SQL functions, WHERE, and JOIN statements to a view and present the data as if the data were coming from one single table.
I use Postgres primarily, so YMMV, but in postgres you need to
1) Create the new schema, preferably owned by the new role, and put the table in it
2) Set the search_path variable to include that schema BEFORE the other one.
Hope it helps.
This is a very bad idea. I'm not sure why people try all these crazy methods to improve security but it's just plain counter productive.
Ultimately every security system comes down to some line like the following if(User.HasAccessTo(object)). In fact, if you've designed a well thought out security system that's almost exactly how it should work. The more disjointed your authentication checks, the more likely you'll make a mistake. If only some users have access to certain record information you should add a flag to those records and verify access based on that.