I have several tables with defined owner user in a SQL Server 2008 database
a_user.[table1]
a_user.[table2]
When I log in as admin I cannot query either table because it doesn't exist [in that user namespace].
How can I make admin or any other user be able to query table a_user.[table1] without referencing the user?
select * from a_user.table1 --> works
select * from table1 --> doesn't work, i'd like this to work
What you're looking at are schemas, not owners. The two concepts are distinct (from SQL Server 2005 onwards).
To resolve any table name, SQL Server will look in your default schema. By default, this will be dbo. The only way to access a table without specifying a schema name is for it to be in your default schema, or for you to add a synonym for the table within your default schema.
Related
I have created a view in Database A that looks at tables in Database B that the users in Database A do not have access to (HR Data).
Is there a way I can grant anybody calling the view in Database A permissions to see the results, without giving access to the underlying tables?
Both databases are on the same instance, SQL Server 2019
You can just
GRANT SELECT ON OBJECT::[schema].[theView] TO User1,User2
in your Database A? This way you'd just give SELECT permissions to the view itself, and not the tables.
If you have a lot of cases like this, you can also consider creating a special schema for this and do:
GRANT select ON Schema :: [DBO] TO User1
instead.
How to create and use Synonyms on PostgreSQL as in Oracle. Do I need to create some DB link or any thing else. I could not find any good official doc on this topic.
Edit 1
Actually as of now i have an application which has two separate modules which connects with two different oracle databases; One modules need to access tables of other so for which we use synonyms over db link in oracle. Now we are migrating application to postgresql, so we need synonyms.
Edit 2
When i say two different oracle databases it means it can be two different oracle instances or two schemas of same db, it is configurable in application and application must support both modes.
PostgreSQL version: 9.6.3
Approach 1:-
Finally i got it working using foreign data wrapper postgres_fdw as below
I have two databases named dba and dbb. dbb has a table users and i need to access it in dba
CREATE SERVER myserver FOREIGN DATA WRAPPER postgres_fdw OPTIONS (host 'localhost', dbname 'dbb', port '5432');
CREATE USER MAPPING FOR postgres
SERVER myserver
OPTIONS (user 'user', password 'password');
CREATE FOREIGN TABLE users (
username char(1))
SERVER myserver
OPTIONS (schema_name 'public', table_name 'users');
CREATE FOREIGN TABLE users (users char(1));
Now i can execute all select/update queries in dba.
Approach 2:-
Can be achieved by creating two schemas in same db, below are the steps:
create two schemas ex app_schema, common_schema.
Grant access:
GRANT CREATE,USAGE ON SCHEMA app_schema TO myuser;
GRANT CREATE,USAGE ON SCHEMA common_schema TO myuser;
Now set search path of user as below
alter user myuser set search_path to app_schema,common_schema;
Now tables in common_schema will be visible to myuser. For example let say we have a table user in common_schema and table app in app_schema then below queries will be running easily:
select * from user;
select * from app;
This is similar to synonyms in oracle.
Note- Above queries will work PostgreSQL 9.5.3+
I think you don't need synonyms in Postgres the way you need them in Oracle because unlike Oracle there is a clear distinction between a user and a schema in Postgres. It's not a 1:1 relationship and multiple users can easily use multiple schemas without the need to fully qualify the objects by exploiting Postgres' "search path" feature - mydb.public.mytable.
If the tables are supposed to be in a different database in PostgreSQL as well, you'd create a foreign table using a foreign data wrapper.
If you used the Oracle synonym just to avoid having to write atable#dblink, you don't have to do anything in PostgreSQL, because foreign tables look and feel just like local tables in PostgreSQL.
If you use the synonym for some other purposes, you can either set search_path to include the schema where the target table is, or you can create a simple view that just selects everything from the target table.
I had a schema in one oracle DB as ui_prod. I asked my DBA team guys to create exactly same schema like ui_prod but as read only and name it ui_prod_readonly. Usually I will use Oracle SQL developer to connect a DB and query directly with table name like below.
--Connect to ui_prod
select * from table
but why I requested to put owner name infront when query for readonly schema they created for me, as without putting it, I get error table not exist.
--Connect to ui_prod_readonly
select * from ui_prod.table
I have project files which hardcode the sql query with only table names and adding owner name in front will cause many changes and effort. Can anyone explain me on this? or provide me any document/link to read. Thanks
You should look into synonyms, apparently the user you are connecting to the database as is not the owner of the objects. So to view the object you have to prepend the names with the schema name (the owner of the object themselves).
http://www.techonthenet.com/oracle/synonyms.php
CREATE OR REPLACE SYNONYM ui_prod_readonly.synonym_name
FOR ui_prod.object_name
It seems to me that your dbas have not created another set of tables but just granted the existing tables to the user ui_prod_readonly.
When you log in to Oracle, the current schema is the name of the user you used to log in. So if you log in with ui_prod_readonly Oracle checks that schema for the table if you do not qualify it with the owner (=schema).
If you want to change the current schema so that you don't need to fully qualify the tables, you can do that with ALTER SESSION
alter session set current_schema = ui_prod;
Once you have done that, you don't need to fully qualify the table with the owner (=schema).
if you need a user to read the data only
its simple to create new user and grant it only select privilege
you can create user and grant select privilege using
CREATE USER [user] IDENTIFIED BY [your_password];
grant select on table to [user]
I want to execute a query that selects data from a different schema than the one specified in the DB connection (same Oracle server, same database, different schema)
I have an python app talking to an Oracle server. It opens a connection to database (server/schema) A, and executes select queries to tables inside that database.
I've tried the following :
select ....
from pct.pi_int, pct.pi_ma, pct.pi_es
where ...
But I get:
ORA-00942: table or view does not exist
I've also tried surrounding the schema name with brackets:
from [PCT].pi_int, [PCT].pi_ma, [PCAT].pi_es
I get:
ORA-00903: invalid table name
The queries are executed using the cx_Oracle python module from inside a Django app.
Can this be done or should I make a new db connection?
Does the user that you are using to connect to the database (user A in this example) have SELECT access on the objects in the PCT schema? Assuming that A does not have this access, you would get the "table or view does not exist" error.
Most likely, you need your DBA to grant user A access to whatever tables in the PCT schema that you need. Something like
GRANT SELECT ON pct.pi_int
TO a;
Once that is done, you should be able to refer to the objects in the PCT schema using the syntax pct.pi_int as you demonstrated initially in your question. The bracket syntax approach will not work.
In addition to grants, you can try creating synonyms. It will avoid the need for specifying the table owner schema every time.
From the connecting schema:
CREATE SYNONYM pi_int FOR pct.pi_int;
Then you can query pi_int as:
SELECT * FROM pi_int;
Depending on the schema/account you are using to connect to the database, I would suspect you are missing a grant to the account you are using to connect to the database.
Connect as PCT account in the database, then grant the account you are using select access for the table.
grant select on pi_int to Account_used_to_connect
If I run a sql script in SQL Server 2005 SSMS (Version 9.00.4035.00) like
CREATE TABLE xxx.MyTable
the table will be created as dbo.MyTable although the schema xxx does exist! No error message!
The user I'm using to run the script as all permissions (tested with windows user and sql user with server role sysadmin)
What's wrong?
You probably have 2 tables now
xxx.MyTable
dbo.MyTable
To check:
SELECT SCHEMA_NAME(schema_id), name, create_date, modify_date
FROM sys.objects
WHERE name = 'MyTable'
Don't rely on SSMS Object Explorer: it needs refreshed (right click on the tables node, refresh).
Or wrong database, wrong server etc.
We use schemas and never had any problems
Edit: now check all databases
EXEC sp_msforeachdb '
USE ?
SELECT SCHEMA_NAME(schema_id), name, create_date, modify_date
FROM sys.objects
WHERE name = ''MyTable''
'
Please take a look at the possible workarounds:
1) Create a SQL login with dbo rights to the database where tables and other objects have to be created. Have the users connect to SSMS using the SQL login that you have created. Tables can be created using SSMS without issues.
2) Have the user of windows security group create table using TSQL. You will see that a new schema and user will be created for this database with the user name of the user. Table gets created with windows user name as the owner .
Now, go to the database user which got created. Change the default schema to xxx.
User of that security group can create tables in SSMS and with dbo as the object owner.
Apparently, this is a microsoft bug and has not been resolved yet.
https://connect.microsoft.com/feedback/viewfeedback.aspx?FeedbackID=238246&wa=wsignin1.0&siteid=68
Hope this helps.