Re: select/insert/delete

From: Robert Freeman <robertgfreeman_at_yahoo.com>
Date: Tue, 7 Jun 2011 23:46:31 -0700 (PDT)
Message-ID: <449042.91376.qm_at_web113201.mail.gq1.yahoo.com>

Ok.... How about something like this.... it's a quick and dirty... I'd throw in exception clauses and so on, but in the little testing I did it seemed to work. Basically I created a function called in the WHERE clause of the MERGE function. It uses the (undefined) pk of the from table to delete the row. I tried to use the ROWID but that generated an ORA error.....

drop table insert_into;
drop table insert_from;

create table insert_into (id number, id_two number); create table insert_from (id number, id_two number);

insert into insert_from values (1,2);
insert into insert_from values (2,3);
commit;

MERGE INTO insert_into D

   USING (SELECT id, id_two, rowid FROM insert_from) S    ON (D.id = S.id)
   WHEN MATCHED THEN UPDATE SET D.id_two = S.id_two    WHEN NOT MATCHED THEN INSERT (D.id, D.id_two) VALUES (1,S.id)      WHERE (fu_delete_value('TEST','INSERT_FROM',s.id)=0);

create or replace function fu_delete_value (p_owner varchar2, p_table_name varchar2, p_rowid number)
return number
as

     v_sql varchar2(2000);
begin

     v_sql:='delete from '||p_owner||'.'||p_table_name||' where id='||p_rowid;
     execute immediate v_sql;
     return 0;

end;

 Robert G. Freeman
Master Principal Consultant, Oracle Corporation, Oracle ACE Author of various books on RMAN, New Features and this shorter signature line. Blog: http://robertgfreeman.blogspot.com

Note: THIS EMAIL IS NOT AN OFFICIAL ORACLE SUPPORT COMMUNICATION. It is just the opinion of one Oracle employee. I can be wrong, have been wrong in the past and will be wrong in the future. If your problem is a critical production problem, you should always contact Oracle support for assistance. Statements in this email in no way represent Oracle Corporation or any subsidiaries and reflect only the opinion of the author of this email.

---

From: Michael Moore <michaeljmoore_at_gmail.com> To: Robert Freeman <robertgfreeman_at_yahoo.com> Cc: david_at_databasesecurity.com; oracle-l_at_freelists.org Sent: Tue, June 7, 2011 9:49:48 PM
Subject: Re: select/insert/delete

Hi Robert,
not really seeing how that accomplishes a DELETE.

Again, what I am attempting to accomplish is to COPY some records from table A into table B and then DELETE those records from table A. I was looking for a single SQL statement that does not use functions or triggers. I don't believe it is possible, but I'm just checking with the group.

Regards,
Mike

On Tue, Jun 7, 2011 at 6:40 PM, Robert Freeman <robertgfreeman_at_yahoo.com> wrote:

Something like:
>
>
>MERGE INTO ...
> USING (
> SELECT ...
> UNION
> SELECT ...
> )
>ON (...)
>WHEN MATCHED THEN UPDATE ...
>WHEN NOT MATCHED THEN INSERT ...
>
>
>
> Robert G. Freeman
>Master Principal Consultant, Oracle Corporation, Oracle ACE
>Author of various books on RMAN, New Features and this shorter signature line.
>Blog: http://robertgfreeman.blogspot.com
>
>
>Note: THIS EMAIL IS NOT AN OFFICIAL ORACLE SUPPORT COMMUNICATION. It is just the
>opinion of one Oracle employee. I can be wrong, have been wrong in the past and
>will be wrong in the future. If your problem is a critical production problem,
>you should always contact Oracle support for assistance. Statements in this
>email in no way represent Oracle Corporation or any subsidiaries and reflect
>only the opinion of the author of this email.
>
>
>
>
>

---

 From: Michael Moore <michaeljmoore_at_gmail.com>
>To: david_at_databasesecurity.com
>Cc: oracle-l_at_freelists.org
>Sent: Tue, June 7, 2011 6:36:52 PM
>Subject: Re: select/insert/delete
>
>
>I guess technically those don't involve a context switch however they're not
>exactly the 'pure sql' solution I was half hoping for. However, you got me
>thinking about the the trigger's performance if a do a bulk insert. Hmmm, I'll
>have to do some testing,
>
>
>Thanks,
>Mike
>
>
>On Tue, Jun 7, 2011 at 4:52 PM, David Litchfield <david_at_databasesecurity.com>
>wrote:
>
>On 08/06/2011 00:47, David Litchfield wrote:
>>
>>On 08/06/2011 00:12, Michael Moore wrote:
>>>
>>>I think the answer to this is NO, but just to be sure,
>>>>
>>>>Is there a single SQL statement that can:
>>>>
>>>>1) SELECT row-X from table A
>>>>2) INSERT row-X into table B
>>>>3) DELETE row-X from table A
>>>>
>>>>It would be nice to be able to do this without a context switch.
>>>>

Yes you can... but it requires a bit of trickery (a function that'll execute arbitrary sql)... Follow the example below...
>>
>

Or you could use a trigger to fire after an insert on table_b to delete to data in table_a... Which is probably the more sane way of doing it, lol :)
>>
>>HTH,
>>David
>>
>>--
>>http://www.freelists.org/webpage/oracle-l
>>
>>
>>
>

--
http://www.freelists.org/webpage/oracle-l

Received on Wed Jun 08 2011 - 01:46:31 CDT