Aaron Bono wrote:
On 12/1/06, *Stephan Szabo* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> 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.
INSERT INTO endTable SELECT * FROM (SELECT convertStartToEnd(st.*)
FROM startTable)
that should work too
Hi Aaron --
I had actually tried your approach earlier, or something very similar:
INSERT INTO endTable SELECT et.* FROM (SELECT convertStartToEnd(st.*)
FROM startTable st) AS et;
Which is basically the same as you suggest, plus an alias ("et") for the
subquery that postgresql was asking for. But it gave the same type
mismatch result as I posted about.
Turns out Stephan's suggestion did the trick.
Cheers,
Chris
