use strict;
use warnings;
use DBI;
require Carp;
require v5.014_000;

my $dbh = DBI->connect(
	"dbi:SQLite:db=:memory:",
	"", "", {
		AutoCommit => 0,
		RaiseError => 1,
		PrintError => 0,
	}
);
defined $dbh or die "No dbh: failed database setup!";

printf( "SQLite DBD version: %s (%s)\n",
	$dbh->{sqlite_version},
	$DBD::SQLite::VERSION
);

# SQLite FK boilerplate setup follows.
# Here the PRAGMA is called to enable foreign_keys.
# However, PRAGMA will work on unknown/unsupported values.
# Thus we have to check that it actually got set if we care.

# With RaiseError, encapsulate DB work in eval:
eval {
	# Attempt to enable FK support:
	$dbh->do( 'PRAGMA foreign_keys(1)' );

	# Now query the actual value:
	my $fk_row = $dbh->selectrow_arrayref( 'PRAGMA foreign_keys' );
	defined $fk_row or die "FK verify query failed. Should not happen.";

	# And verify FK support is now enabled:
	die "SQLite FK support is still disabled!" unless ($fk_row->[0] == 1);

	# Indicate success if we got here, and disconnect to be nice.
	print "Success: FK support was enabled as intended.\n";
	$dbh->disconnect;
};

# Handle errors from DB work above: (safe as of Perl >=5.14.0.)
if ($@) {
	my $err = $@;
	# attempt rollback, avoids needless warnings:
	eval { $dbh->rollback };
	# report the error and a backtrace:
	Carp::confess( "DB work error: $err" );
}