UPDATE category SET 
  chrCat_Full_Name=UPPER(LEFT(chrCat_Full_Name,1))
  +LOWER(RIGHT(chrCat_Full_Name,DATALENGTH(chrCat_Full_Name)+1))

##</code><code>##

use DBI;
require DBD::ODBC; ## will be done auto, but doesn't hurt to check.

my $db  = DBI->connect($dsn,'','',{RaiseError=>1});
my $db2 = DBI->connect($dsn2,'','',{RaiseError=>1});

my $sql ="SELECT * FROM category";
my $sth = $db->prepare($sql);
$sth->execute();

## ? is a placeholder that will be auto-quoted later!
my $sql2 = 'update category set chrCat_Full_Name=? where chrCategory_Code=?';

## now we get the DBI ready to execute that statement many times with different placeholders
my $sth2 = $db2->prepare($sql2);


while (my $data = $sth->fetchrow_hashref()) {
   ## the parameters passed will be quoted and substituted
   ## for the placeholders in order
   $sth2->execute(
      ucfirst( lc($data->{'chrCat_Full_Name'}) ),
      $data->{'chrCategory_Code'}
   );

   ## this won't show your parameters, to do that you can trace
   ## or just explicitly print them.
   print "$sql2 $data->{'chrCat_Full_Name'}\n";
}

$db->disconnect;
$db2->disconnect;