I am login with a user abc in a database xyz with Oracle SQL Developer. How can I get the usernames of the schema through which I am logged in?
I believe by usernames you mean operating system usernames. Username in Oracle database (and SQL Developer), is a synonym to the schema name.
So in your case, your schema called abc. Now assume your operating system username is 'John', and you want to know other users who are connected to the schema 'abc', then you can run the query:
SELECT osuser
FROM v$session
WHERE schemaname = 'abc';
Refer to this post for more details
If you just want to know the list of users in the schema you are in, try this:
SELECT * FROM all_users
If you do not change current schema the following code will be fine:
-- In PLSQL
DECLARE
vv_SchemaName VARCHAR2(100);
BEGIN
vv_SchemaName := Sys_Context('USERENV','CURRENT_SCHEMA');
dbms_output.put_line(vv_SchemaName);
END;
-- IN SQL
SELECT Sys_Context('USERENV','CURRENT_SCHEMA') FROM DUAL
Current_schema is a bit different from LOGGED USER see the example:
-- The output will be:
-- Current schema:LOGGED_SCHEMA session user:LOGGED_SCHEMA
-- Current schema:CHANGED_SCHEMA session user:LOGGED_SCHEMA
-- When you are connected to LOGGED_SCHEMA and have CHANGED_SCHEMA.
DECLARE
vv_SchemaName VARCHAR2(100);
vv_SessionUser VARCHAR2(100);
BEGIN
vv_SchemaName := Sys_Context('USERENV','CURRENT_SCHEMA');
vv_SessionUser := Sys_Context('USERENV','SESSION_USER' );
dbms_output.put_line('Current schema:' || vv_SchemaName || ' session user:' || vv_SessionUser);
EXECUTE IMMEDIATE 'ALTER SESSION SET CURRENT_SCHEMA=CHANGED_SCHEMA';
vv_SchemaName := Sys_Context('USERENV','CURRENT_SCHEMA');
vv_SessionUser := Sys_Context('USERENV','SESSION_USER' );
dbms_output.put_line('Current schema:' || vv_SchemaName || ' session user:' || vv_SessionUser);
END;
So If you plan to connect to one user and work on another one than depending on your needs using Sys_Context('USERENV','SESSION_USER' ) may be a better option.
Related
How to execute
GRANT SELECT ON <ownschema>.<sometable> TO <somerole>;
but backing off gracefully if somerole does not exist. The user executing the statement is a standard user (think SCOTT) without any special privileges.
Version: Oracle Database 19 or later
I don't think you can.
If you're running it at SQL level, then Oracle will raise an error if role doesn't exist.
If you want to check whether it exists, you'll need some kind of a PL/SQL procedure (which is not a problem), but - DBA should grant you select privilege on dba_roles so that you could check it. Then, if it exists, you'd grant that privilege; otherwise, return some kind of an information (dbms_output.put_line in my example is pretty much stupid; it wouldn't be visible out of SQL*Plus, SQL Developer, TOAD and similar), but you got the idea, I hope.
Something like this:
create or replace procedure p_grant_to_role (par_role in varchar2) is
l_cnt number;
begin
select count(*)
into l_cnt
from dba_roles
where role_name = par_role;
if l_cnt > 0 then
execute immediate 'grant select on emp to ' || par_role;
else
dbms_output.put_line('Role does not exist');
end if;
end;
/
It all depends on the tool, but you can do something like this (very crude as usually you should have better exception handling):
begin
execute immediate 'grant .....';
exception
when others then null;
end;
Hi so i have the following plan :
i want to Write a script, which calls another script. A parameter V_USERNAME should be passed from the 1st script to the 2nd script.( Using the keyword DEFINE)
My code look like :
##C:\Users\pe.k\Documents\script2.sql &p_v_username
set serveroutput on
define p_v_username = "user";
In the 2nd script all tables of the user should be output. (Using the key word EXECUTE IMMEDIATE and a cursor).
The output control is to be done via a parameter in the script or when calling the script.
Example call:
SQL> #start_script1 MML
declare
&p_v_username varchar2(100);
v_result varchar2(100);
cursor cp_username (&p_v_username varchar2)
is
select owner, table_name
from all_tables
where owner = &p_v_username
order by owner, table_name;
begin
dbms_output.put_line('Alle Tabellen der User'); --l_username);
open cp_username(&p_v_username);
--loop
--fetch cp_username into v_result;
-- dbms_output.put_line(v_result);
--end loop;
close cp_username;
end;
/
And i have the errors and i am lost. I dont know how to do it
Your second procedure should be something like this:
BEGIN
DBMS_OUTPUT.PUT_LINE('Alle Tabellen der User'); --l_username);
FOR TABS IN (
SELECT OWNER, TABLE_NAME
FROM ALL_TABLES
WHERE OWNER = '&P_V_USERNAME'
ORDER BY OWNER, TABLE_NAME
) LOOP
DBMS_OUTPUT.PUT_LINE(TABS.TABLE_NAME);
END LOOP;
END;
/
In order to print the output generated by the DBMS_OUTPUT package from PL/SQL, make sure to set serveroutput on
I am new to Oracle database, got a task to write several selects, but I do not get somethow principle, how it works (or better to say does not work). Could you please help me to find a mistake and probably you have a link to some info or converter that helps such writings.
v_sql := 'SELECT ''DROP TABLE ''||object_name||'' as
select *
FROM all_objects
WHERE object_name LIKE '''%''|| v_date ||''%'''
and object_type = ''TABLE''
and owner =''||v_owner||''';
Are you trying to generate DROP statements for a specific user? Start with the below anonymous block and add to it.
--Generate DROP statements for all tables for a user.
declare
v_owner varchar2(128) := user;
begin
for objects in
(
select distinct 'DROP TABLE "'||owner||'"."'||object_name||'"' v_sql
from all_objects
where object_type = 'TABLE'
and owner = v_owner
order by v_sql
) loop
dbms_output.put_line(objects.v_sql);
end loop;
end;
/
set serveroutput on;
declare
username1 varchar2(40);
cnt number;
hello varchar2(20);
c sys_refcursor;
begin
select sys_context('userenv','session_user') into username1 from dual;
select lower(username1) into username1 from dual;
select count(lower(username)) into cnt from karuna.tableusers where lower(username)=username1;
if cnt=1 then
dbms_output.put_line('username found');
execute immediate 'connect karuna/password ';
open c for 'select item_name from sells12 where item_id=12';
fetch c into hello;
dbms_output.put_line(hello);
close c;
else
dbms_output.put_line('u dont have previllege to access database');
----raise_application_error(-20001,'error out');
end if;
end;
/
I want to switch session user but I am getting error at connect karuna/karuna line
Look at Oracle's feature n-tier (proxy) authentication. Maybe it's not what you need. Oracle offers you:
n-tier auth
set role statement (to get more privs. from password "protected" roles)
alter session set current_schema=KARUMA. This will not switch your username/privs but the default schema.
The right choice really depends on your needs.
you have to give dba privilege to connect from your user to KARUMA user or CONNECT privilege.
please follow this link
http://docs.oracle.com/cd/B28359_01/java.111/b31224/proxya.htm
Here is the definition of the stored procedure:
CREATE OR REPLACE PROCEDURE usp_dropTable(schema VARCHAR, tblToDrop VARCHAR) IS
BEGIN
DECLARE v_cnt NUMBER;
BEGIN
SELECT COUNT(*)
INTO v_cnt
FROM all_tables
WHERE owner = schema
AND table_name = tblToDrop;
IF v_cnt > 0 THEN
EXECUTE IMMEDIATE('DROP TABLE someschema.some_table PURGE');
END IF;
END;
END;
Here is the call:
CALL usp_dropTable('SOMESCHEMA', 'SOME_TABLE');
For some reason, I keep getting insufficient privileges error for the EXECUTE IMMEDIATE command. I looked online and found out that the insufficient privileges error usually means the oracle user account does not have privileges for the command used in the query that is passes, which in this case is DROP. However, I have drop privileges. I am really confused and I can't seem to find a solution that works for me.
Thanks to you in advance.
SOLUTION:
As Steve mentioned below, Oracle security model is weird in that it needs to know explicitly somewhere in the procedure what kind of privileges to use. The way to let Oracle know that is to use AUTHID keyword in the CREATE OR REPLACE statement. If you want the same level of privileges as the creator of the procedure, you use AUTHID DEFINER. If you want Oracle to use the privileges of the user currently running the stored procedure, you want to use AUTHID CURRENT_USER. The procedure declaration looks as follows:
CREATE OR REPLACE PROCEDURE usp_dropTable(schema VARCHAR, tblToDrop VARCHAR)
AUTHID CURRENT_USER IS
BEGIN
DECLARE v_cnt NUMBER;
BEGIN
SELECT COUNT(*)
INTO v_cnt
FROM all_tables
WHERE owner = schema
AND table_name = tblToDrop;
IF v_cnt > 0 THEN
EXECUTE IMMEDIATE('DROP TABLE someschema.some_table PURGE');
END IF;
END;
END;
Thank you everyone for responding. This was definitely very annoying problem to get to the solution.
Oracle's security model is such that when executing dynamic SQL using Execute Immediate (inside the context of a PL/SQL block or procedure), the user does not have privileges to objects or commands that are granted via role membership. Your user likely has "DBA" role or something similar. You must explicitly grant "drop table" permissions to this user. The same would apply if you were trying to select from tables in another schema (such as sys or system) - you would need to grant explicit SELECT privileges on that table to this user.
You should use this example with AUTHID CURRENT_USER :
CREATE OR REPLACE PROCEDURE Create_sequence_for_tab (VAR_TAB_NAME IN VARCHAR2)
AUTHID CURRENT_USER
IS
SEQ_NAME VARCHAR2 (100);
FINAL_QUERY VARCHAR2 (100);
COUNT_NUMBER NUMBER := 0;
cur_id NUMBER;
BEGIN
SEQ_NAME := 'SEQ_' || VAR_TAB_NAME;
SELECT COUNT (*)
INTO COUNT_NUMBER
FROM USER_SEQUENCES
WHERE SEQUENCE_NAME = SEQ_NAME;
DBMS_OUTPUT.PUT_LINE (SEQ_NAME || '>' || COUNT_NUMBER);
IF COUNT_NUMBER = 0
THEN
--DBMS_OUTPUT.PUT_LINE('DROP SEQUENCE ' || SEQ_NAME);
-- EXECUTE IMMEDIATE 'DROP SEQUENCE ' || SEQ_NAME;
-- ELSE
SELECT 'CREATE SEQUENCE COMPTABILITE.' || SEQ_NAME || ' START WITH ' || ROUND (DBMS_RANDOM.VALUE (100000000000, 999999999999), 0) || ' INCREMENT BY 1'
INTO FINAL_QUERY
FROM DUAL;
DBMS_OUTPUT.PUT_LINE (FINAL_QUERY);
cur_id := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.parse (cur_id, FINAL_QUERY, DBMS_SQL.v7);
DBMS_SQL.CLOSE_CURSOR (cur_id);
-- EXECUTE IMMEDIATE FINAL_QUERY;
END IF;
COMMIT;
END;
/
you could use "AUTHID CURRENT_USER" in body of your procedure definition for your requirements.
Alternatively you can grant the user DROP_ANY_TABLE privilege if need be and the procedure will run as is without the need for any alteration. Dangerous maybe but depends what you're doing :)