Summary of Programming Perl DBI--a simple database manipulation program

#! /usr/bin/perl -w
#######mysql database manipulation program using Programming Perl DBI
#######you can modify/redistribute it as perl itself
use strict;
use DBI;
sub get_choice
{
   my $option;
   print STDOUT "Please select a Choice for songwolf database:\n";
   print STDOUT "1==========retrive information of specific id=====================\n";
   print STDOUT "2==========update name of specific id=============================\n";
   print STDOUT "3==========delete record of corresponds to a specific id==========\n";
   print STDOUT "4==========insert a new record====================================\n";
   print STDOUT "others=====exit the program======================================\n";
   chomp($option = <>);
   $option;
}

sub db_manipulate()
{
  my $dbh = shift;
  my $option = shift;
  if($option == 1)
  {
     &do_select($dbh);
  }
  elsif($option == 2)
  {
     &do_update($dbh);
  }
  elsif($option == 3)
  {
     &do_delete($dbh);
  }
  elsif($option == 4)
  {
     &do_insert($dbh);
  }
   else
  {
     print STDOUT "--------exiting from the program---------------\n";
     exit 0;
  }
}

sub do_select()
{
  my $dbh = shift;
  my $id=undef;
  print STDOUT "you've selected the retrive option\n";
  print STDOUT "Please input the test_id of which the information you want to retrive:\n";
  chomp($id = <>);
  my $sth = $dbh->prepare("select test_id id,name name from test where test_id= ?") or die "can't prepare select sql statement:$DBI::errstr\n";
  $sth->bind_param(1,$id);
  $sth->execute() or die "can't execute select statement:$DBI::errstr\n";
  my ($result_id,$result_name) = $sth->fetchrow_array();
  {
      if(defined($result_id))
      {
       print "test_id $result_id is of name $result_name\n";
       $sth->finish();
      }
      else
      {
          print "no test record corresponds to the specified test_id\n";
      }
  }
}

sub do_update()
{
    my $dbh = shift;
    my ($id,$new_name);
    print STDOUT "you've selected the update option\n";
    print STDOUT "please enter the test_id of the corresponding record you want to update\n";
    chomp($id = <>);
    print STDOUT "please enter the new name for the specified test_id:\n";
    chomp($new_name=<>);
    my $sth = $dbh->prepare("update test set name= ? where test_id = ? ") or
     die "can't prepare update statement:$DBI::errstr\n";
    $sth->bind_param(1,$new_name);
    $sth->bind_param(2,$id);
    $sth->execute() or warn "can't execute update statement\n";
    $sth->finish();
    ####my $rows = $dbh->do("update test set name= '".$new_name."' where test_id =".$id");
    ####if($rows < 1 ) {print STDOUT "no rows updated\n";
}

sub do_delete()
{
    my $dbh = shift;
    my $id;
    print STDOUT "you've selected the delete option\n";
    print STDOUT "please enter the test_id of the corresponding record you want to delete\n";
    chomp($id = <>);
    my $rows = $dbh->do("delete from test where test_id = ".$id);
    print STDOUT "deleted $rows rows from database\n";
}

sub do_insert()
{
    my $dbh = shift;
    my ($id,$new_name);
    print STDOUT "you've selected the insert option\n";
    print STDOUT "please enter the test_id of the new record\n";
    chomp($id = <>);
    print STDOUT "please enter the name for the new record\n";
    chomp($new_name=<>);
    my $sql = "insert into test (test_id,name) values (".$id.",'".$new_name."')";
    my $rows = $dbh->do($sql);
    print STDOUT "inserted $rows rows into the database\n";
}

my $dbh = DBI->connect("DBI:mysql:database=songwolf;host=localhost;msql_configfile=/etc/init/mysql.conf;mysql_compression=1","songwolf","2613481") or die "can not connect to database:$DBI::errstr\n";
while(1)
{
    my $choice = &get_choice;
    eval{&db_manipulate($dbh,$choice)};
    print "caught error:$@\n" if $@;
}
$dbh->disconnect() or warn "can't disconnect from database:$DBI::errstr\n";