use strict;
use warnings;
use DBI;

#1
my $dbh = DBI->connect ("dbi:SQLite:Test.sqlite");
die "connect failed: $DBI::errstr" if ! $dbh;

#2
local $dbh->{AutoCommit} = 0;    # Use transacted processing
local $dbh->{RaiseError} = 1;    # die on processing errors
local $dbh->{PrintError} = 0;    # Suppress printing errors

#3
my $sql =
    qq{CREATE TABLE People (name VARCHAR(128), age INTEGER)};

#4
eval {
    $dbh->do ($sql);
    $dbh->commit ();
};

#5
if ($@) {
    # An error occurred
    $dbh->rollback ();
    die $@;
}

##</code><code>##

local $dbh->{RaiseError} = 1;
local $dbh->{PrintError} = 0;
eval {
    $dbh->begin_work;
    ... queries go here ...
    $dbh->commit;
    1;
} or do {
    my $err = $@ || "Unknown error";
    eval {
        $dbh->rollback;
        1;
    } or do {
        $err .= "[ROLLBACK FAILED: " . ($@ || "Unknown reasons") . "]";
    }
    die $err;
}

##</code><code>##

use strict;
use warnings;
use DBI;

my $dbh = DBI->connect ("dbi:SQLite:Test.sqlite");
die "connect failed: $DBI::errstr" if ! $dbh;
$dbh->{AutoCommit} = 0;    # Use transacted processing
$dbh->{RaiseError} = 1;    # die on processing errors

my %people = (
    Fred  => 23,
    Jane  => 22,
    Boyd  => 27,
    Tania => 28,
    Julie => 27,
    Kyle  => 21,
);

#1
my $sql = qq{INSERT INTO People (name, age) VALUES (?, ?)};

my $entries = 0;

eval {
    my $sth = $dbh->prepare ($sql); #2

    while (my ($name, $age) = each %people) { #3
        ++$entries if $sth->execute ($name, $age); #4
    }

    $dbh->commit (); #5
    return 1;
} or do {
    my $err = $@ || "Unknown error inserting data";
    
    eval {$dbh->rollback ()} or $err .= "\n   Rollback processing failed!";
    die $err;
};

print "Added $entries rows to the People table\n";

##</code><code>##

$entries = $sth->execute_array ({}, [keys %people], [values %people]);

##</code><code>##

#1
my $sql = qq{SELECT name, age FROM People WHERE name LIKE ? AND age < ?};

eval {
    #2
    my $sth = $dbh->prepare ($sql);

    $sth->execute ('%e', 25); #3

    #4
    while (my $row = $sth->fetchrow_hashref ()) {
        printf "%-10s %3d\n", @{$row}{'name', 'age'};
    }
};