Hi Sandy_Bio_Perl,

I think that the problem isn't with the IS NOT NULL, but rather with the division on the column with the null value. Here's something I scratched together that works. Note the IFNULL in your SQL statement, as well as csv_null => 1 in the connection parameters:

#!/usr/bin/perl

use strict;
use warnings;
use DBI;

sub RunSqlSearch;


my $spreadsheet = 'newCsv.csv'; 
my $query 
    = "SELECT sid,genotype, dnabl, dnatw12 "
    . "FROM $spreadsheet "
    . "WHERE genotype = 'a' "
    . "AND (IFNULL(dnatw12,0)/dnabl)<0.5 "
    . "AND dnatw12 IS NOT NULL "
    ;   
my ($queryResult) = RunSqlSearch($query);
print "Your query $query returned the following result:\n$queryResult\
+n";

sub RunSqlSearch($){
    
    my $query = $_[0]; 
    
    # error check #
    if ($query eq ""){die "From runSqlQuery2 -  No value entered for $
+query $!\n";}
        
    # Connect to the database, (the directory containing our csv file(
+s))
    my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
        f_dir            => ".",
        f_encoding       => "utf-8",
        csv_eol          => "\n",
        csv_null         => 1,
        RaiseError       => 1,
        }) or die $DBI::errstr;
    
    # Output using sql query #
    my $sth = $dbh->prepare($query);
    $sth->execute;
    
    my @row;
    my $queryResult="";
    while (@row = $sth->fetchrow_array) {
        $queryResult .= join("\t",@row) . "\n";
    }  
        
    # output arguments #
    if ($queryResult eq ""){$queryResult = "No result found";}
    return ($queryResult);
}

[download]

Hope that points you in the right direction.

-bmt

UPDATE: Note that this will still blow up if dnabl is NULL. I played around a bit, but the IFNULL that worked in the numerator of the division failed to work in the denominator. Not sure why...

In reply to Re: DBD::CSV::st execute failed: Can't locate object method "do_err" via package "SQL::Statement::Function::NumericEval" by BaldManTom
in thread DBD::CSV::st execute failed: Can't locate object method "do_err" via package "SQL::Statement::Function::NumericEval" by Sandy_Bio_Perl

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.