IDS Forum

Re: Random name for temp table

Posted By: Art Kagel
Date: Thursday, 20 March 2014, at 4:29 p.m.

In Response To: Re: Random name for temp table (VIKAS HIVARKAR)

Don't use a FOREACH. Build the SELECT in a string, PREPARE it, DECLARE a
cursor against the prepared statement, then OPEN cursorname and use a FOR
or WHILE loop to FETCH cursorname INTO ... inside the loop, EXIT out of the
look if SQLCODE != 0 after the FETCH, RETURN whatever you need to return,
then CLOSE the cursor and FREE it before returning from the function. You
can check error conditions using SQLCODE as well when it is < 0 (100 ==
end-of-data).

Here's a link to an article about this:

http://www.ibm.com/developerworks/data/library/techarticle/dm-0806mottupalli/index.html

Art

Art S. Kagel, Principal Consultant
ASK Database Management

Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on the IIUG, nor any other organization with which I am
associated either explicitly, implicitly, or by inference. Neither do
those opinions reflect those of other individuals affiliated with any
entity with which I am affiliated nor those of the entities themselves.

On Thu, Mar 20, 2014 at 4:03 PM, VIKAS HIVARKAR <vikas.hivarkar@gmail.com>wrote:

> Hi Art and Marcus
>
> I am just trying with the dynamic statement testing in the SP however there
> are 14 places this table is used in an "INSERT INTO vikas......" and I
> believe
> all these INSERTS will also have to be prepared dynamically which is easy
> but
> I am struggling with the last part of SP with also need the temp table
> "vikas"
>
> ORIGINAL SNIPPET
>
> FOREACH cursor for SELECT (NVL(v_label, ' ') ||' '||'::'||' '||
> NVL(v_text, '
> '))
>
> INTO v_output
>
> FROM vikas
>
> ORDER BY v_sr_no
>
> RETURN v_output WITH RESUME;
>
> END FOREACH;
>
> I am trying different ways to replace this in to a dynamic statement and
> execute but every option I try gives me a syntax error on the RETURN or END
> FOREACH line;
>
> Regards,
>
>
> =============================================================================
>
> Duh, of course, you did say it was all in the same session.. I was
> originally going to have the proc use the userid of the actual user to name
> the temp table, but thought better of that as each user could have more
> than one connection to the java service so opted for session id which won't
> work <sigh>. OK, um how about the java thread id for the thread servicing
> the particular client or whatever cookie value the service is using to link
> the data back to the correct user? Pass that into the function and build
> the temp table name from that. You can also have a proc to drop the temp
> tables that are no longer needed when the users' connection to the service
> is broken.
>
> Art
>
> Art S. Kagel, Principal Consultant
> ASK Database Management
>
> Blog: http://informix-myview.blogspot.com/
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions
> and do not reflect on the IIUG, nor any other organization with which I am
> associated either explicitly, implicitly, or by inference. Neither do
> those opinions reflect those of other individuals affiliated with any
> entity with which I am affiliated nor those of the entities themselves.
>
> On Thu, Mar 20, 2014 at 2:16 PM, VIKAS HIVARKAR
> <vikas.hivarkar@gmail.com>wrote:
>
> > Hi Art,
> >
> > Your solution is simply genius, I am just thinking if the developer is
> > opening
> > one session and all the users are using that session that could it be
> > possible
> > that the parent session established with database remains the same and
> > hence
> > the session id remains the same, In such case the vikas_<sessionid> will
> > remain same.
> >
> > I am just simulating the scenario and will check the results.
> >
> > The SP takes a integer as passed by the users and I though of using that
> in
> > the table name because it is unlikely (but still possible) that the user
> > searches for the same integer
> >
> > > drop procedure create_tab (integer);
> >
> > Routine dropped.
> >
> > > CREATE PROCEDURE create_tab (table_name integer)
> > > DEFINE l_crtstmt CHAR(1024);
> > > LET l_crtstmt = "CREATE TEMP TABLE vikas_" ||table_name|| "(col1
> > integer)";
> > > EXECUTE IMMEDIATE l_crtstmt;
> > > END PROCEDURE;
> >
> > Routine created.
> >
> > > EXECUTE PROCEDURE create_tab (12345);
> >
> > Routine executed.
> >
> > > select count(*) from vikas_12345;
> >
> > (count(*))
> >
> > 0
> >
> > 1 row(s) retrieved.
> >
> > This is exactly what you suggested using dynamic prepare statement and
> will
> > use the integer as passed by the users but still not fool proof.
> >
> > I dont know if there is a ready made function in v12 that gives me a
> random
> > number which is very unlikely to repeat in quick successions
> >
> > Regards,
> > Vikas
> >
> >
> >
> ============================================================================
> >
> > create procedure make_temp() return lvarchar;
> > define sid bigint;
> > define tmp_stmt, tmpname lvarchar;
> >
> > select dbinfo('sessionid') into sid from sysmaster:sysdual;
> >
> > let tmpname = 'vikas_" || sid::lvarchar;
> >
> > let tmp_stmt = "create temp table vikas_" || tmpname || " (v_sr_no
> > SMALLINT,v_label VARCHAR(200), v_text LVARCHAR(2000) default null) WITH
> NO
> > LOG";
> >
> > execute immediate tmp_stmt;
> > return tmpname;
> >
> > end procedure;
> >
> > Art S. Kagel, Principal Consultant
> > ASK Database Management
> >
> > Blog: http://informix-myview.blogspot.com/
> >
> > Disclaimer: Please keep in mind that my own opinions are my own opinions
> > and do not reflect on the IIUG, nor any other organization with which I
> am
> > associated either explicitly, implicitly, or by inference. Neither do
> > those opinions reflect those of other individuals affiliated with any
> > entity with which I am affiliated nor those of the entities themselves.
> >
> > On Thu, Mar 20, 2014 at 2:41 AM, VIKAS HIVARKAR
> > <vikas.hivarkar@gmail.com>wrote:
> >
> > > Hi All,
> > >
> > > Informix 12.10.FC2 on HP Unix 11.31
> > >
> > > I have a stored procedure running file for 2 years which creates a temp
> > > table
> > > with no log
> > >
> > > CREATE TEMP TABLE vikas(
> > > v_sr_no SMALLINT,
> > > v_label VARCHAR(200),
> > > v_text LVARCHAR(2000) default null) WITH NO LOG;
> > >
> > > Now One of our developers have written a java code for GUI based
> > > application
> > > that calls this procedure and for some reasons he has used a single
> > session
> > > polling login that opens a single session to the database and all the
> > users
> > > use this session.
> > >
> > > There starts the trouble as the temp table is session based it cannot
> be
> > > used
> > > by mutiple users and the funtion fails
> > >
> > > Until the connection logic is fixed, Is there any way I can modify the
> > > stored
> > > procedure to create a temp table with random name instead of the hard
> > coded
> > > "vikas" name
> > >
> > > I was looking for the funtion DBMS_RANDOM_RANDOM but not sure how to
> use
> > it
> > > also there is "IF NOT EXISTS" but I dont know if it has any relevance
> > with
> > > my
> > > issue.
> > >
> > > Regards,
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

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Messages In This Thread

• Random name for temp table
  VIKAS HIVARKAR -- Thursday, 20 March 2014, at 2:41 a.m.
  • Re: Random name for temp table
    Marcus Haarmann -- Thursday, 20 March 2014, at 3:29 a.m.
  • Re: Random name for temp table
    Art Kagel -- Thursday, 20 March 2014, at 7:23 a.m.
    • Re: Random name for temp table
      VIKAS HIVARKAR -- Thursday, 20 March 2014, at 2:16 p.m.
      • Re: Random name for temp table
        Marcus Haarmann -- Thursday, 20 March 2014, at 2:25 p.m.
      • Re: Random name for temp table
        Art Kagel -- Thursday, 20 March 2014, at 2:30 p.m.
        • Re: Random name for temp table
          VIKAS HIVARKAR -- Thursday, 20 March 2014, at 4:03 p.m.
          • Re: Random name for temp table
            Art Kagel -- Thursday, 20 March 2014, at 4:29 p.m.

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