The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.
 / 
MongoDB-0.29
River stage two • 48 direct dependents • 56 total dependents
88 ++
/ MongoDB::DataTypes

NAME

MongoDB::DataTypes - the data types used with MongoDB

DESCRIPTION

This goes over the types you can save to the database and use for queries.

TYPES

Dates

The DateTime package can be used insert and query for dates. Dates stored in the database will be returned as instances of DateTime.

An example of storing and retrieving a date:

    use DateTime;

    my $now = DateTime->now;
    $collection->insert({'ts' => $now});

    my $obj = $collection->find_one;
    print "Today is ".$obj->{'ts'}->ymd."\n";

An example of querying for a range of dates:

    my $start = DateTime->from_epoch( epoch => 100000 );
    my $end = DateTime->from_epoch( epoch => 500000 );

    my $cursor = $collection->query({event => {'$gt' => $start, '$lt' => $end}});

Regular Expressions

Use qr/.../ to use a regular expression in a query:

    my $cursor = $collection->query({"name" => qr/[Jj]oh?n/});

Regular expressions will match strings saved in the database.

You can also save and retrieve regular expressions themselves:

    $collection->insert({"regex" => qr/foo/i});
    $obj = $collection->find_one;
    if ("FOO" =~ $obj->{'regex'}) { # matches
        print "hooray\n";
    }

Note for Perl 5.8 users: flags are lost when regular expressions are retrieved from the database (this does not affect queries or Perl 5.10).

Booleans

Use the boolean pachage to get boolean values. boolean::true and boolean::false are the only parts of the package used, currently.

An example of inserting boolean values:

    use boolean;

    $collection->insert({"okay" => true, "name" => "fred"});

An example using boolean values for query operators (only returns documents where the name field exists):

    my $cursor = $collection->query({"name" => {'$exists' => boolean::true}});

Other

There are a few Mongo-specific data types.

MongoDB::OID

"OID" stands for "Object ID", and is a unique id that is automatically added to documents if they do not already have an _id field before they are saved to the database. They are 12 bytes which are guarenteed to be unique. Their string form is a 24-character string of hexidecimal digits.

To create a unique id:

    my $oid = MongoDB::OID->new;

To create a MongoDB::OID from an existing 24-character hexidecimal string:

    my $oid = MongoDB::OID->new("123456789012345678901234");

MongoDB::MinKey

MongoDB::MinKey is "less than" any other value of any type. This can be useful for always returning certain documents first (or last).

MongoDB::MinKey has no methods, fields, or string form. To create one, it is sufficient to say:

    bless $minKey, "MongoDB::MinKey";

MongoDB::MaxKey

MongoDB::MaxKey is "greater than" any other value of any type. This can be useful for always returning certain documents last (or first).

MongoDB::MaxKey has no methods, fields, or string form. To create one, it is sufficient to say:

    bless $minKey, "MongoDB::MaxKey";