Deleting federated objects - IBM db2 PLSQL - plsql

I am working with IBM db2.
I have some scripts which are implemented like this:
begin
execute immediate 'CREATE WRAPPER MY_WRAPPER';
execute immediate 'CREATE SERVER SERVER390 TYPE DB2/ZOS VERSION 7.1 WRAPPER MY_WRAPPER AUTHORIZATION "APP_USER" PASSWORD "secret" OPTIONS (DBNAME 'remotedb');';
execute immediate 'CREATE USER MAPPING FOR PUBLIC SERVER SERVER390 OPTIONS (REMOTE_AUTHID ‘APP_USER', REMOTE_PASSWORD ‘secret');';
execute immediate 'CREATE NICKNAME ASSIGN for SERVER390.db_schema.ASSIGN';
end
I want to be able to check and delete everything (wrapper, server, user mapping, nickname assign), in case it exists (avoind errors if the objects don't exist).
What would be the best way?

Related

ORA-22285: non-existent directory or file for FILEOPEN operation

I am trying to insert code of XML file into a column which is of XMLtype
I have below query which is working fine
select extract(xmlcol,'/*')
from (SELECT xmltype(BFILENAME('MEDIA_DIR', 'xmldata1.xml'),nls_charset_id('UTF-8')) xmlcol FROM dual)
On running this query I am getting the Xmlcode inside the xml file(xmldata1) in one row.
Now, As per my requirement I have created a type which reads data from the XMLfile.
Below is the code of member function of the type:
create or replace type body t_emp
as
member function get_xml return xmltype is
v_xml xmltype;
begin
select extract(xmlcol,'/*') into v_xml
from (SELECT xmltype(BFILENAME('MEDIA_DIR', 'xmldata1.xml'),nls_charset_id('UTF-8')) xmlcol FROM dual);
return v_xml;
end get_xml;
end;
I am calling this type member function in my code. Below is the code
declare
t_emp1 t_emp;
r1 xmltype;
begin
t_emp1 := t_emp(2);
r1 := t_emp1.get_xml;
insert into EMPLOYEE_XML values (t_emp1.id,r1);
end;
Here variable r1 is of importance as I am fetching XML data in this variable.
On running this code I am getting below error:
ORA-22285: non-existent directory or file for FILEOPEN operation
I am not able to understand why this error is coming as the directory exist. I am able to run previously mentioned SQL query.
Thanks!!
The user you are creating the type as only has permissions on the directory object granted through a role. Privileges from roles are not inherited by stored PL/SQL blocks by default. When you run the SQL directly the role is enabled; when you run in through the PL/SQL member function the role is disabled and the directory is not visible to your user. You need the directory privileges to be granted directly to your user.
In your case you are working in the SYSTEM schema (so the directory privilege is coming via the EXP_FULL_DATABASE role, which comes from DBA), which is a bad idea; it is not good practice to create objects in that schema (or any built-in schema), so granting privileges directly to `SYSTEM would also be a mistake here.
You should create a new user/schema, with the minimum privileges it needs. You've already created the directory object, so the new user set-up would include:
grant read,write on media_dir to your_new_user;
You can then create the type and its member function in that new schema, and you'll be able to execute it from your anonymous block.
If you can only have privileges granted through a role then you could instead change the type declaration to use invoker's rights
create or replace type t_emp authid current_user as object ...
That would even work in your current scenario, sticking with SYSTEM; but again you really shouldn't be working in that schema.

SP Not Found When It Clearly Exists

I copied a database from a live MSSQL server to my local one, and was able to log in correctly. I am having a problem however in that when it is time to call a stored procedure the Asp.Net application keeps telling me the SP does not exist, when it clearly does.
I am using windows authentication but on the server I was using credentials, could this be the problem?
Also, all of the SP's have my online username attached to their name, as in username.StoredProcedurenName.
Please help I have been trying to fix this for hours.
I just noticed that when I attempt to run the SP from the SQL Management Studio it works, but it appends the username to the SP such as:
USE [DBNAME]
GO
DECLARE #return_value int
EXEC #return_value = [username].[SPNAME]
SELECT 'Return Value' = #return_value
GO
If I remove the username, it says the same thing (SP not found). How do I get around this?
I suspect you are calling your stored procedure without specifying the schema. When calling a stored procedure (or accessing a table, view, etc) that's not in the default schema that your account is configured for, usually dbo, you need to explicitly include the schema like the sql command below
SqlCommand cmd = new SqlCommand("username.StoredProcedurenName", mySqlConnection);
It's likely what Jason said. The solution has to do with rights and ownership. When you see the SP in the SQL Management Studio, under Programmability->Stored Procedures, your SP should have a prefix like "dbo." or "GateKeeper."
If the SP has "dbo." as the prefix, the user account with which you're connecting to the DB just be part of the database owners (dbo) group, otherwise you won't have access to it. So, you can either add the user to that group, or create the stored procedure ("create procedure spBlahBlah as ..") using the account to plan to run the program under; when you call it you use "exec GateKeeper.spBlahBlah" to stipulate the Schema.StoredProcedureName.
Those are your two choices.

Reference different schema using "alter session set current_schema" inside a package

Is it possible to do
alter session set current_schema=MySchema;
inside a package?
Our asp.net web application call Oracle packages. We'd like to connect to database with an Oracle user that is not the owner of MySchema. For that, we grant execute permissions on Other_User to package MyPackage.
Example:
grant execute on MySchema.MyPackage to Other_User
But when web app connects to Oracle and try to execute the stored procedures of MyPackage, it gets errors because tables don't belong to Other_User.
One way to avoid errors is creating synonyms, but we would prefere to use
alter session set current_schema=MySchema;
if possible, inside the package.
EDIT: When trying to put "alter session" in package:
You cannot use DDL statements (which ALTER SESSION is) directly in PL/SQL.
You need to use an EXECUTE IMMEDIATE:
execute immediate 'alter session set current_schema=MySchema';

Adding tempdb items on startup in SQL Server

How could I add some items to the tempdb anytime SQL Server starts up?
I'm no expert at this, but our ASP SessionState is stored in the DB and for some reason the tempdb items used for the session state get dropped anytime the server restarts. Not only do I need to recreate the items, but I also have to recreate the User mappings to tempdb. I have a script that does it, but I can't figure out how to run it on SQL startup
-- Use TempDB
use tempdb
go
-- Create Temp tables if they don't exist
IF NOT EXISTS(
SELECT 1 FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE='BASE TABLE'
AND TABLE_NAME = 'ASPStateTempSessions')
BEGIN
EXECUTE [ASPState].[dbo].[CreateTempTables]
END
-- If ASPSessionState user isn't mapped to temp db, map it
IF IS_MEMBER('ASPSessionState') IS NULL
create user ASPSessionState from login ASPSessionState
-- Give ASPSessionState user read/write permissions to tempdb
exec sp_addrolemember db_datareader, ASPSessionState
go
exec sp_addrolemember db_datawriter , ASPSessionState
go
Um, if you've used the standard settings to enable ASP.Net session state in tempdb, the system should have generated a stored proc (ASPState_Startup) as follows in the master database. This stored proc is configured to run automatically on SQL Server startup:
USE master
GO
DECLARE #sstype nvarchar(128)
SET #sstype = N'sstype_temp'
IF UPPER(#sstype) = 'SSTYPE_TEMP' BEGIN
DECLARE #cmd nchar(4000)
SET #cmd = N'
/* Create the startup procedure */
CREATE PROCEDURE dbo.ASPState_Startup
AS
EXECUTE ASPState.dbo.CreateTempTables
RETURN 0'
EXEC(#cmd)
EXECUTE sp_procoption #ProcName='dbo.ASPState_Startup', #OptionName='startup', #OptionValue='true'
END
So, the temp tables should be being recreated anyway, unless something has been altered since installing.
If additional permissions are required, I'd look to extending the existing CreateTempTables procedure in ASPState.
If this isn't working correctly, you might try using the aspnet_regsql command (found under %Windir%\Microsoft.Net\Framework\<framework version - to remove then re-add session state support to the server. You'd want to use -ssremove then -ssadd, but I'd suggest passing /? first to see all of the applicable options.

Why does my tempdb reset permissions when the server is rebooted?

The past two times we have rebooted our sql server, our website has gone down. The reason appears to be because the tempdb is getting recreated and the ASPState user is losing permission to read/write to the tempdb (it is an ASP site and session data is stored in the sql server)
This was not a problem until about two weeks ago. Does anyone know how I can prevent the sql server from resetting tempdb permissions after a reboot? Or why this only started happening recently? We are using MS SQL Server 2005.
First off, you shouldn't assign permissions to the tempdb directly. For the obvious reasons that it gets recreated on every reboot.
Which actually raises a question: why do you need to have direct permissions to this database anyway?
You don't need any permissions beyond just being able to connect to sql server in order to create temp tables. However, if you are creating real tables in the tempdb, then I highly suggest you change this to use a dedicated database for this purpose.
UPDATE
Based on Martin's comment all I can say is wow. I would never even have considered that this would have been an option.
Okay, now that I've recovered from the shock.
Create a new job in sql server that executes on a schedule. The schedule should be set to "Start Automatically whenever SQL Server Agent Starts". The job should recreate your necessary tempdb permissions.
In a nutshell, when the server is rebooted the SQL Server Agent will be restarted (provided the service is set that way). When it restarts it will kick off this job that will then fix your permissions. I'd expect the site to remain down for only a few seconds more than it takes for SQL server to completely restart.
I know this is an old question but found some new information regarding the tempdb behaviour on restarting.
The tempdb is essentially recreated from the 'model' db and that is the reason why all changes to it are lost. If you make a change to persist your changes even after restart make the same changes to the 'model' db as you would to the 'tempdb'.
Have a look at the following: Does tempdb Get Recreated From model at Startup?
The Model database is used as a template for TempDB. Add users and permissions to model and the same usere and permissions will be used on TempDB. I do not say that this is the optimal solution for every case but it worked for me in a situation where an application needed speciffic TempDB access.
Create a startup script on sql Server as below:
use master
go
drop proc AddAppTempDBOwner
go
create proc AddAppTempDBOwner as
declare #sql varchar(200)
select #sql = 'use tempdb' + char(13)
+ 'exec sp_addrolemember ''db_owner'', ''app'''
exec (#sql)
go
exec sp_procoption 'AddAppTempDBOwner', 'startup', 'true'
go
Here's a script to create a startup stored procedure, which loops over Logins and creates Users in tempdb as db_owner. This script does not have harcoded logins.
As a result even after SQL machine restarts all SQL logins will have privileges to access tempdb.
USE [master]
GO
IF EXISTS ( SELECT *
FROM sysobjects
WHERE id = object_id(N'AddUsersToTempDb')
and OBJECTPROPERTY(id, N'IsProcedure') = 1 )
BEGIN
DROP PROCEDURE AddUsersToTempDb
END
GO
CREATE PROCEDURE AddUsersToTempDb
AS
DECLARE #loginname as NVARCHAR(100);
DECLARE Login_Cursor CURSOR FOR
SELECT loginname
FROM master..syslogins
OPEN Login_Cursor;
FETCH NEXT FROM Login_Cursor INTO #loginname;
WHILE ##FETCH_STATUS = 0
BEGIN
IF (#loginname <> 'sa' AND (NOT #loginname LIKE '##%') AND (NOT #loginname LIKE '%\%'))
BEGIN
PRINT #loginname
IF EXISTS(SELECT * FROM [tempdb].sys.database_principals WHERE type_desc = 'SQL_USER' AND name = #loginname)
PRINT ' - user already exists'
ELSE
BEGIN
PRINT ' - creating user'
DECLARE #Sql VARCHAR(MAX)
SET #Sql =
'USE Tempdb' + char(13) +
'CREATE USER ' + #loginname + ' FOR LOGIN ' + #loginname + char(13) +
'EXEC sp_addrolemember db_owner, ' + #loginname
EXEC (#Sql)
END
END
FETCH NEXT FROM Login_Cursor INTO #loginname;
END;
CLOSE Login_Cursor;
DEALLOCATE Login_Cursor;
GO
EXEC sp_procoption 'AddUsersToTempDb', 'startup', 'true'
GO
The tempdb database in SQL server is (from everything I've ever read, heard, or experienced) completely dropped and recreated every time the service is started up. Thus, anything stored within or written to that database, including roles, users, or other access right settings, will be wiped out. Barring some fussy code to set/reset them whenever the instance starts up, I don't think you can work around this. (I don't think anything set in the model database gets copied over to tempdb when it's created, but I've never even thought about that...)
Are any such settings being written to that databases? Are you sure that your system has not been recently changed or updated to do so? Possibly relevant, how often does the SQL instance get stopped and restarted? (It's not uncommon--if not wise--for SQL to run for months if not yers without a restart...)

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