I agree.
Tim.
On Mon, Feb 05, 2001 at 03:36:28PM +0800, Reinke Bonte wrote:
> I'm not an experienced programmer, but your suggestion does not make much
> sense to me. Wouldn't your effort be better spent on improving the existing
> chart method? In that way non-dbi-users can use your method without carrying
> around the weight of dbi. And to be honest, I find it rather confusing to
> build charts with SQL statements.
>
> I like your qoute at the beginning!
>
>
> -ren
>
> ----- Original Message -----
> From: "Dean Arnold" <[EMAIL PROTECTED]>
> To: "DBI-users" <[EMAIL PROTECTED]>; "DBI-dev" <[EMAIL PROTECTED]>
> Sent: Monday, February 05, 2001 4:42 AM
> Subject: DBD::Chart ?
>
>
> "The more I do DBD, the more DBDs I do."
> - Frank Sinatra (paraphrased)
>
> I'm embarking on another DBD effort and wanted to get
> some input from the community.
>
> I've been using the Chart::Plot, and GD::Graph modules
> to render charts from database rowsets, but feel like
> there's an impedance mismatch between DBI
> and the charting packages...so I'm whipping up a
> DBD::Chart to try and rectify the situation.
>
> At present, the idea is to use "CREATE TABLE..."
> like syntax to establish the graph domain info,
> use "INSERT..." syntax to add data points,
> and then "SELECT..." syntax to actually render the
> graph image, returning the image as a bytestring
> from $sth->fetch(). All the various chart types
> would be supported (bar, pie, line, scatter, curve),
> and the various chart attributes would be supplied
> in the WHERE clause of the SELECT, e.g.
>
> Example script to render a piechart 300x350 pixels:
>
> $chartdbh = DBI->connect('dbi:Chart');
> $chartdbh->do('CREATE TABLE mychart (value FLOAT, region CHAR(20))');
>
> $dbh = DBI->connect('dbi:Oracle', .etc..);
> $sth = $dbh->prepare('SELECT cust_satisfaction, region FROM region_info');
> my ($satis, $region);
> $sth->bind_cols(\$satis, $region);
>
> $chartsth = $chartdbh->prepare('INSERT INTO mychart VALUES(?, ?)');
> $chartsth->bind_param(1, $satis);
> $chartsth->bind_param(2, $region);
>
> while ($sth->fetch) { $chartsth->execute; }
>
> $piesth = $chartdbh->prepare('SELECT PIECHART FROM mychart ' .
> 'WHERE TITLE='Customer Satisfaction' AND ' .
> 'WIDTH = 300 AND HEIGHT = 350');
> my $chart;
> $piesth->bind_col(1, \$chart);
> $piesth->fetch;
> #
> # now you can save it, or send it back to a browser,
> # stick it in a Perl Tk window...whatever
> #
>
> Example syntax to render an area-filled linegraph
> 400x200 pixels:
> SELECT LINEGRAPH FROM mygraph
> WHERE TITLE='Annual Rainfall' AND
> WIDTH=400 AND HEIGHT=200 AND
> FILL=YES AND POINT='' AND
> X-AXIS='Month' AND Y-AXIS='Inches'
> AND COLOR=blue and SHOWGRID=1
>
> Overlapped graphs could be rendered by
> pseudo-joins of subqueries:
> SELECT IMAGE FROM
> (SELECT LINEGRAPH FROM raingraph
> WHERE TITLE='Annual Rainfall' AND
> FILL=YES AND POINT='+' AND
> X-AXIS='Month' AND Y-AXIS='Inches'
> AND COLOR=blue) A,
> (SELECT LINEGRAPH FROM tempgraph
> WHERE TITLE='Avg. Temperature' AND
> POINT='circle' AND X-AXIS='Month' AND Y-AXIS='Degrees F'
> AND COLOR=red) B
> WHERE WIDTH=400 AND HEIGHT=200 AND SHOWGRID=1
>
> If anyone sees anything wrong with this, or has some
> features they'd like to see included, please drop me a line.
>
> Regards,
> Dean Arnold
>
