Stephan Szabo wrote:
On Fri, 1 Dec 2006, Chris Dunworth wrote:

Hi all --

(huge apologies if this is a duplicate post -- I sent from an
unsubscribed email account before...)

I have a problem trying to INSERT INTO a table by selecting from a
function that returns a composite type. (I'm running version 8.1.4, FYI)

Basically, I have two tables. I want to retrieve rows from one table and
store them into the other. The schema of the two tables is not the same,
so I use a conversion function (written in plperl) that takes a row from
the start table and returns a row from the end table. However, I can't
get the insert working.

Here's a simplified example of my real system (must have plperl
installed to try it):

---------------------------------------
-- Read rows from here...
CREATE TABLE startTable ( intVal integer, textVal text );

-- ...and store as rows in here
CREATE TABLE endTable ( intVal integer, newVal1 integer, newVal2 integer);

-- Some test data for the startTable
INSERT INTO startTable VALUES ( 1, '10:11');
INSERT INTO startTable VALUES ( 2, '20:25');
INSERT INTO startTable VALUES ( 3, '30:38');

-- Note: Takes composite type as argument, and returns composite type.
-- This just converts a row of startTable into a row of endTable, splitting
-- the colon-delimited integers from textVal into separate integers.
CREATE OR REPLACE FUNCTION convertStartToEnd(startTable) RETURNS
endTable AS $$
   my ($startTable) = @_;
   my @newVals = split(/:/, $startTable->{"textval"});
   my $result = { "intval"=>$startTable->{"intval"},
"newval1"=>@newVals[0], "newval2"=>@newVals[1] };
   return $result;
$$ LANGUAGE plperl;
---------------------------------------

Now, if I run the following SELECT, I get the results below it:

SELECT convertStartToEnd(st.*) FROM startTable st;

convertstarttoend
-------------------
(1,10,11)
(2,20,25)
(3,30,38)
(3 rows)

This seems OK. But when I try to INSERT the results of this select into
the endTable, I get this error:

INSERT INTO endTable SELECT convertStartToEnd(st.*) FROM startTable st;


I think you'd need something like
 INSERT INTO endTable SELECT (convertStartToEnd(st.*)).* FROM startTable
 st;
to make it break up the type into its components.


Yes! That was exactly it. I thought it might have been something simple.

Thanks, Stephan!

-Chris

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