[ic] Order of columns for hashref returned from query?
Kyle Cook
interchange-users@interchange.redhat.com
Thu Apr 18 04:22:00 2002
At 11:15 PM 4/17/02, you wrote:
> > From: interchange-users-admin@interchange.redhat.com
>[mailto:interchange-
> > users-admin@interchange.redhat.com] On Behalf Of Kyle Cook
> >
> > At 06:15 PM 4/17/02, you wrote:
> > >I'm working on a piece of code that will be called by CommonAdjust to
> > >only return the columns in the pricing table which are populated with
> > >data for the given item. This will force the quantity discount
> > >mechanism to discount quantity orders which are equal to or exceed a
> > >previous price break. I had this code working before, but it used a
> > >$Tag->data call for each column which was inefficient to do. Below
>is
> > >the code as it stands right now. It selects the data then outputs
>the
> > >columns. It will be modified to only output the columns that have a
> > >value once I find a solution to the problem.
> > >
> > >[perl tables=pricing]
> > > my $code = $Scratch->{tmp_code};
> > > my $available_breaks =
> > >"q2,q3,q4,q5,q6,q7,q8,q9,q10,q12,q15,q25,q50,q100";
> > > my $sql = "SELECT " . $available_breaks . "
>FROM
> > >pricing WHERE sku ='" . $code . "';";
> > > my $sql_results = $Tag->query( { sql =>
> > >$sql, hashref => 'price_results' } );
> > > my $hash = $sql_results->[0];
> > > my $out = "";
> > > my $key, $value;
> > > while ( ($key, $value) = each %$hash ) {
> > > $out .= " $key => $value ";
> > > }
> > > #foreach $key (sort keys %$hash) {
> > > # $out .= " $key => $$hash{$key} ";
> > > #}
> > > return $out;
> > > [/perl]
> > >
> > >The problem with this code is the ordering of the hash does not match
> > >the ordering of the column list in the select statement. It is
>output
> > >in this order:
> > >
> > >q15,q9,q25,q50,q2,q3,q10,q4,q5,q12,q6,q7,q100,q8,
> >
> > Ron,
> >
> > My bad, I missed the part where only some columns will be used, hmmm
> > next best try would be using a sort subroutine like:
> >
> > foreach $key (sort {$$hash{$a} <=> $$hash{$b}} keys %$hash) {
> >
> > This will force the keys to be compared numerically, ignoring the
> > 'q' at the beginning.
> >
> > Kyle Cook
>
>Thanks for the help Kyle! I tried your suggestion and the results were
>sorted on the value instead of the key. I searched for examples of
>sorting on the key and found some, but all the keys in the examples were
>strings. My attempts to modify your example to do a numerical search on
>the keys did not work either. Looks like I need to do some reading on
>hashes and sorting :)
>
>While I was relaxing it hit me, why not just split on the comma in my
>available_breaks and then loop over those values and key into the hash
>to see if the there is a price break. Below is the code that I came up
>with:
>
> [seti tmp_code][item-code][/seti]
> [perl tables=pricing]
> my $out = "pricing:price_group,";
> my $code = $Scratch->{tmp_code};
> my $available_breaks =
>"q2,q3,q4,q5,q6,q7,q8,q9,q10,q12,q15,q25,q50,q100";
> my $break;
> my $sql = "SELECT " . $available_breaks . " FROM
>pricing WHERE sku ='" . $code . "';";
> my $sql_results = $Tag->query( { sql =>
>$sql, hashref => 'price_results' } );
> my $hash = $sql_results->[0];
> my @breaks = split (/,/, $available_breaks);
> foreach $break (@breaks) {
> if ($$hash{$break} ne '') {
> $out .= "$break,";
> }
> }
> return $out;
> [/perl]
>
>Thanks again and I'll post the usertag once it's complete :)
>-Ron
Sorry, thats what you get from someone up way past his bed time :)
Should have been:
foreach $key (sort {$a <=> $b} keys %$hash) {
Kyle