Shell Programming and Scripting

#!/usr/bin/perl -w
use DBI;
my $primac = "6666.5555.4444";
my $dbh = DBI->connect("DBI:mysql:myDB","username","password",) or die $DBI::errstr;
my $force = $dbh->do("SELECT forcewrite FROM table WHERE primac = '$primac'") or die $DBI::errstr;
print "$force\n";

#!/usr/bin/perl -w
use DBI;
my $primac = "6666.5555.4444";
my $dbh = DBI->connect("DBI:mysql:myDB","username","password",) or die $DBI::errstr;
my $sth = $dbh->prepare("SELECT forcewrite FROM admin WHERE primac = '$primac'") or die $DBI::errstr;
$sth->execute() or die  $DBI::errstr;
my $force = ($sth->fetchrow_array())[0];
print "$force\n";

my $force;

my $dbh = DBI->connect("DBI:mysql:myDB","username","password",) or die $DBI::errstr;

my $sth = $dbh->prepare("SELECT forcewrite FROM table WHERE primac = '$primac") || die "Error parsing SQL: $DBI::errstr\n";

$sth->execute() || die "Error executing SQL: $DBI::errstr\n";

$sth->bind_col(1, \$force  ) || die "Error binding variable: $DBI::errstr\n";

while ( $sth->fetch ) {
    print "force = $force\n";
}

$
$ mysql -u test -ptest -e "select nic from t where ip = '3.3.3.3'" test
+------+
| nic  |
+------+
| CE0  |
+------+
$
$ cat -n fetchone.pl
     1  #!/usr/bin/perl -w
     2  use DBI;
     3  $dbh = DBI->connect('dbi:mysql:test','test','test');
     4  my $nic = $dbh->selectrow_array("select nic from t where ip = '3.3.3.3'");
     5  print "nic = $nic\n";
     6
$
$ perl fetchone.pl
nic = CE0
$
$