Perl efficient DB Call

I wrote the below script to update the file.
The script works but I had a small concern with the script I wrote, it makes multiple database calls.
Is there any way you think I can modify this and make just one DB call.

This is what the script currently does:

1)      Go thru each line of the file and get the 3 fields that are required ($fields[6], $fields[8], $fields[12])
2)      Run query and get the results using the 3 fields
3)      Print output file line by line by appending the results at the end of each line.

#!/usr/bin/perl

use 5.006;
use strict;
use warnings;
use Pod::Usage;
use Getopt::Long;
use Cwd;
use DateTime;
use DBD::mysql;
use DBI;

my $helpme = 0;
my $man = 0;
my $inputFileName = 'C:\\temp\\test.txt';
my $outputFileName = 'C:\\temp\\output.txt';
my $dsn = 'DBI:ODBC:Driver={SQL Server}';
my $host = 'testdb';
my $database = 'MYAPP';
my $user = 'admin';
my $auth = 'p@ssword';


GetOptions('help' => \$helpme, 'man' => \$man, 'infile=s' => \$inputFileName, 'outfile=s' => \$outputFileName) or pod2usage(2);

pod2usage(1) if $helpme;
pod2usage(-verbose => 2) if $man;

die "No input file name specified!" if !$inputFileName;
die "No output file name specified!" if !$outputFileName;
my $dbh = DBI->connect("$dsn;Server=$host;Database=$database", $user, $auth,{ RaiseError => 1, AutoCommit => 1}) || die "Database connection not made: $DBI::errstr"; 

open(INFILE, "<", $inputFileName) || die "Could not open input file!";
open(OUTFILE, ">", $outputFileName) || die "Could not open/create output file!";

while (<INFILE>) {
    chomp;
   my @fields = split /\s*\|\s*/; 
   my $sql = "SELECT e.id1, d.id2, s.id3   
              FROM  Employee e 	
              JOIN  Department d 
                      ON d.did = '$fields[12]' AND d.status ='A'
              JOIN  Student s  
                      ON s.sid= '$fields[6]' AND s.status ='A'	 
              Where e.eid= '$fields[8]' AND e.status ='A'";
   my $sth = $dbh->prepare($sql);
   $sth->execute();
   while (my @row = $sth->fetchrow_array) {
    print OUTFILE $_."|".$row[0]."|".$row[1]."|".$row[2]."\n";
   }    
}
close INFILE;
close OUTFILE;

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Thanks,