Hi thanks I tried this way,it still does not enter the while loop to print the statement:print "Entering taxID_format with $t\n";

LOOP:foreach $ref(@ref)
{
 print "in foreach loop with $ref\n";

  $count=0;

  $command1 = qq{select distinct tax_id from gene2acc where genomic_ac
+_ver= '$ref'; }; 
   $sth1=$dbh->prepare($command1);

              $sth1->execute() or die $sth1->errstr;

              my($tax_id);

              $sth1->bind_columns(undef,\$tax_id );

              while($sth1->fetch())

              {     

                $t=$tax_id;

                print "Entering taxID_format with $t\n";


                #&taxID_format($t);

               

              }
[download]

please help me