how can we identified schema name in sybase ase 15.5? - database-schema

I am trying to get schema name in sybase database.
First I have create login(user1) from sa user and than i have connect with user1 by giving login name(user1) and password now i have tried to create table by giving following command:-
create table user1.table1(
emp_id int not null,
name varchar(80) not null
)
but it was showing access denied error than i have logged-in from sa user and grant sa_role to user1 and then again i have run above mention query for create table and table were created successfully.
here I am not exactly getting that user1 is schema name or not or how can I identified schema name?
I want to also know that is there any role except sa_role for grant create insert delete table ,views and all other objects of sybase database.

Sybase ASE does not use the schema concept that SQL Server and Oracle use. Objects are located inside a database, and owned by a user - no other logical separations are there. So your syntax is wrong.
create table table1
(
emp_id int not null,
name varchar(80) not null
)
Sybase ASE Create Table
Additionally, Sybase/SAP best practices tells us all database objects should be created/owned by dbo with permissions granted to groups/roles/users to access those objects. Users who own database objects can not be removed, so if User1 gets fired, you will have to identify all the objects he owns, and change the ownership of those objects before his account can be deleted.
So for your example, the dbo user (typically sa) would create the objects, then GRANT permissions (INSERT/UPDATE/DELETE/etc) to the groups/roles/users who need access.
More information on managing user permissions can be found in the Sybase ASE System Administrators Guide Vol 1.
And more information about Roles/Groups from the System Admin Guide.

Related

Using CREATE SCHEMA AUTHORIZATION

Can I use CREATE SCHEMA AUTHORIZATION for something other than the current user's schema?
I can do the following:
CREATE USER MAIN_USER
IDENTIFIED BY main_user_pass;
GRANT CREATE SESSION TO MAIN_USER;
GRANT CREATE TABLE TO MAIN_USER;
ALTER SESSION SET CURRENT_SCHEMA = MAIN_USER;
Query 1:
SELECT USER FROM DUAL;
Result 1:
SYS
Query 2:
SELECT sys_context( 'userenv', 'current_schema') FROM dual;
Result 2:
MAIN_USER
I can do this:
CREATE SCHEMA AUTHORIZATION SYS
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY);
Result:
Schema AUTHORIZATION created.
But when I try to do this, an error appears:
CREATE SCHEMA AUTHORIZATION MAIN_USER
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY);
Result:
ORA-02421: missing or invalid schema authorization identifier
02421. 00000 - "missing or invalid schema authorization identifier"
*Cause: the schema name is missing or is incorrect in an authorization
clause of a create schema statement.
*Action: If the name is present, it must be the same as the current
schema.
The error message is pretty clear: you can't do that. From the documentation:
The schema name must be the same as your Oracle Database username.
Setting current_schema only changes the default schema name prepended to an object reference in a SQL command that isn't fully qualified, so after setting it to MAIN_USER, this command:
select * table table_a;
would be interpreted as
select * from main_user.table_a;
instead of
select * from sys.table_a;
Setting current_schema doesn't actually change your logged in identity or affect your privileges in any way, and if sys can't execute a command like that against another schema then nobody can do it.
Can I use CREATE SCHEMA AUTHORIZATION for something other than the current user's schema?
No, you can't. The documentation says:
Use the CREATE SCHEMA statement to create multiple tables and views and perform multiple grants in your own schema in a single transaction.
This statement lets you populate your schema ...
Specify the name of the schema. The schema name must be the same as your Oracle Database username.
You have to be connected as the schema owner, so user returns MAIN_USER. Just changing your current schema with ALTER SESSION SET CURRENT_SCHEMA is not sufficient.
It also says:
To issue a CREATE SCHEMA statement, you must have the privileges necessary to issue the included statements.
and you have granted CREATE TABLE so that should work once you connect as that user. But it means you can't rely on the privileged SYS user's CREATE ANY privs to bypass the schema grants, which might have been an advantage had it been allowed to work as you hoped; if you want your user to end up without those privileges you'll have to grant them, run CREATE SCHEMA as that user, then revoke them again. Or go back to individual CREATE object statements, which you can run for another user as SYS - but without the all-or-nothing single-transaction benefit you get from CREATE SCHEMA.

Permission denied for relation <table_name>

So I'm making this app and I'm using Postgres and I've already created a database, a user and a password and granted all privileges on the database to the user I've created.
The thing is, when I switch the database in psql using \c <database_name> I get in just fine and can use queries on it.
But when I run psql using postgres://user_name:password#localhost:5432/databasename on terminal and try to select * from the <table_name> it gives me this message
permission denied for relation <table_name>
Can you please tell me what to do, I've had this problem before and I had to create another database or change the user but I want a better solution please.
PS: I've tried to use this :
GRANT ALL PRIVILEGES ON TABLE <table_name> to <user_name>
This is how I created and accessed my database:
rawan95=# create database food ;
CREATE DATABASE
rawan95=# create user meal with password '123';
CREATE ROLE
rawan95=# grant all privileges on database food to meal;
GRANT
rawan95=# \c food
You are now connected to database "food" as user "rawan95".
After that, I've built it using
food=# \i src/database/db_build.sql
BEGIN
DROP TABLE
CREATE TABLE
INSERT 0 1
COMMIT
Then I selected data from the table just fine, but when I try to access it using this, I get an error: psql postgres://meal:123#localhost:5432/food
food=> select * from foods;
ERROR: permission denied for relation foods
You are granting the privileges before you create the tables.
As there are no tables at that moment nothing is granted. The tables you created are not owned by the user meal but the user rawan95 (which the \c command told you).
Plus: granting "all privileges" on a database, does not grant any select privilege. As documented in the manual "all privileges" are: CREATE, CONNECT, TEMPORARY, TEMP. The CREATE privilege would allow the user meal to create tables in that database.
If you want all those tables to be owned by the user meal you need to run your setup script after you connected as the user meal (the \c command did not change the current user)
If you do want rawan95 to be the owner of the tables, you need to either grant the select privilege after creating all tables:
grant select on all tables in schema public to meal;
Or, you can change the default privilege before creating the tables (before running db_build.sql), so that they are applied to all tables in the future:
alter default privileges in schema public
grant select on all tables to meal;
The alter default privileges only has an effect for tables that are created after that. So to fix your current setup, you need to first grant select on the existing tables, and the change the default privileges for all tables that are created in the future.
Have you granted usage on the schema? Without that the table permissions are useless.
GRANT USAGE ON SCHEMA schema_name TO username
EDIT: Based on comment thread below we have established.
The table is in public schema.
The table belongs to rawan95 but the schema does not (public schema belongs to root postgres user).
The OP is attempting to connect and access the table as user 'meal' they have granted table permissions using the rawan95 user but are unable to grant schema permissions.
From the above, the problem could still be that the user 'meal' does not have usage on the public schema. If you are on Linux the quickest way to sort this is to switch to the super user to make this change from terminal:
sudo -u postgres psql -c "GRANT USAGE ON SCHEMA public TO meal"
FURTHER EDIT - having read your new clarification this is not correct (or at least not useful). The issue is as pointed out by the other answerer that you didn't have a table at the time you did the grant.

Separate and restrict data access using schemas

I am an Oracle DBA, new to PostgreSQL. I have a requirement to separate some modules data, so that one module will not have access to read the data of another module.
I read about the use of schemas in PostgreSql which is somewhat different than the use of it in Oracle. However seems like it is recommended to use the method of different schemas for separation and management - just like in Oracle.
However, when I create 2 schemas - connected to the same database and same user - I can do a select from the other schema's table.
That is, for example, if I have schema A owning table a, and schema B owning table b, when I set the search path to schema B I can do a select on schema’s A table a without any problem.
I couldn't find a way to revoke this privilege from schema B.
The only I could find then to separate access to data, is using different roles, that is to create role A with schema A, and role B with schema B. then I can grant and revoke access from user B in order for it to see what I want from role's A tables.
Is this correct? Am I missing something?
if I have schema A owning table a
A schema does not "own" a table in Postgres - a user does. This is the same as in Oracle - the difference (and maybe where your confusion arises) is that in Oracle in a regular user can't create tables outside of a schema that has the same name as the user account.
So if user arthur creates a table in schema_a and one in schema_b, both tables are owned by arthur - not "the schema".
If you used different schemas/users in Oracle to separate data and to prevent access to the other user's tables, then you need two users and two schemas in Postgres as well.
The default search_path in Postgres is setup in a way, that (unqualified) tables are always first searched (and created) in a schema with the same name as the user running the statement.
So if you create two users and a schema with the user's name for each user, you pretty much have the same setup as in Oracle:
create user arthur with password 'foobar';
create schema arthur authorization arthur; --<< this is what Oracle does "automatically"
create user bob with password 'verysecret';
create schema bob authorization bob;
Now, if bob creates a table, that table is created in the schema bob and is owned by the user bob. User arthur has not privileges to access that table.
If you never need to share data between those users (or schemas), then you can create two databases, create two users and let both users create everything in the public schema of "their" database.

Postgresql user with specific privileges

In Postgresql how would I create a user that can do everything expect create roles, drop databases, drop roles, drop tables but it can create a database.
Essentially this user will be used to access a database for an application that stores, updates and retrieves data and the user can create a database.
You create a user and make that user the owner of the database:
The following has to be done as a superuser:
create user arthur password 'verysecret';
create database arthur_db owner = arthur;
Now arthur can do anything in that database.

Alter Table Of Other User in Firebird

When I try to alter a table from a different owner in Firebird I got this error:
unsuccessful metadata update
MODIFY RDB$RELATION_FIELDS failed
no permission for control access to TABLE TAGS
I had already granted ALL privileges to this user, also REFERENCES privileges, but I still getting this error.
Does anybody knows how to solve this?
I use Firebird 1.5
Thanks
The Firebird 2.5 Language Reference section on ALTER TABLE states:
Only the table owner and administrators have the authority to use
ALTER TABLE.
In other words if you are not the owner of the table, you need to either login as SYSDBA, or you need to be logged in as root or Adminstrator on the machine with the database. There is - as far as I am aware - no other way to alter a table as a different user.
In Firebird 2.5 there is also the RDB$ADMIN role which allows a user which is granted this role to act with the same rights as SYSDBA.
The rights you can GRANT (except for REFERENCES) are only for DML, not for DDL operations.
Firebird 3 introduced metadata privileges, which allows you to grant these permissions to a specific user or role for specific object types.
For example:
GRANT ALTER ANY TABLE TO Joe;
Will allow the user Joe to alter any tables in the current database.