CREATE TABLE students (
	name TEXT NOT NULL PRIMARY KEY,
	hometown TEXT NOT NULL,
	grade TEXT,
	data JSONB NOT NULL DEFAULT '{}'::jsonb
);

##</code><code>##

use Mojo::Pg;

my $pg = Mojo::Pg->new('postgres://localhost:54321/testing')
	->password('BarFoo');

$pg->db->insert('students', {
	name => 'Bob Kowalski',
	hometown => 'Vero Beach, FL',
	data => { -json => {
		hobbies => [ 'ham radio', 'Python programming', 'running' ],
	} },
});
$pg->db->insert('students', {
	name => 'Kranessa Evans',
	hometown => 'Dallas, TX',
	data => { -json => {
		hobbies => [ 'Perl programming', 'writing', 'polo' ],
	} },
});

my $res = $pg->db->select('students')->expand;
while ( my $rec = $res->hash ) {
	if ( grep {/perl/i} @{ $rec->{data}{hobbies} } ) {
		$pg->db->update('students', { grade=>'A' },
			{ name=>$rec->{name} } );
	}
}
$res->finish;

##</code><code>##

$ docker run --rm -p54321:5432 --name pgtestdb -e POSTGRES_PASSWORD=FooBar -d postgres:13
# wait a few seconds for it to start
$ echo "CREATE USER $USER PASSWORD 'BarFoo'; CREATE DATABASE testing; GRANT ALL PRIVILEGES ON DATABASE testing TO $USER;" | psql postgresql://postgres:FooBar@localhost:54321
$ psql postgres://localhost:54321/testing
# log in and create the above table
# run the above Perl script
$ PGPASSWORD=BarFoo psql postgres://localhost:54321/testing -c 'SELECT * FROM students'
$ docker stop pgtestdb