DOKK / manpages / debian 12 / libmango-perl / Mango::Cursor::Query.3pm.en

User Contributed Perl Documentation

NAME

Mango::Cursor::Query - MongoDB query cursor

SYNOPSIS

  use Mango::Cursor::Query;
  my $cursor = Mango::Cursor::Query->new(collection => $collection);
  my $docs   = $cursor->all;

Mango::Cursor::Query is a container for MongoDB query cursors used by Mango::Collection.

Mango::Cursor::Query inherits all attributes from Mango::Cursor and implements the following new ones.

  my $await = $cursor->await_data;
  $cursor   = $cursor->await_data(1);

Await data.

  my $comment = $cursor->comment;
  $cursor     = $cursor->comment('Fun query!');

A comment to identify query.

  my $fields = $cursor->fields;
  $cursor    = $cursor->fields({foo => 1});

Select fields from documents.

  my $hint = $cursor->hint;
  $cursor  = $cursor->hint({foo => 1});

Force a specific index to be used.

  my $max = $cursor->max_scan;
  $cursor = $cursor->max_scan(500);

Limit the number of documents to scan.

  my $max = $cursor->max_time_ms;
  $cursor = $cursor->max_time_ms(500);

Timeout for query in milliseconds.

  my $query = $cursor->query;
  $cursor   = $cursor->query({foo => 'bar'});

Original query.

  my $pref = $cursor->read_preference;
  $cursor  = $cursor->read_preference({mode => 'SECONDARY'});

Read preference.

  my $skip = $cursor->skip;
  $cursor  = $cursor->skip(5);

Number of documents to skip, defaults to 0.

  my $snapshot = $cursor->snapshot;
  $cursor      = $cursor->snapshot(1);

Use snapshot mode.

  my $sort = $cursor->sort;
  $cursor  = $cursor->sort({foo => 1});
  $cursor  = $cursor->sort(bson_doc(foo => 1, bar => -1));

Sort documents, the order of keys matters.

  my $tailable = $cursor->tailable;
  $cursor      = $cursor->tailable(1);

Tailable cursor.

Mango::Cursor::Query inherits all methods from Mango::Cursor and implements the following new ones.

  my $query = $cursor->build_query;
  my $query = $cursor->build_query($explain);

Generate final query with cursor attributes.

  my $clone = $cursor->clone;

Clone cursor.

  my $count = $cursor->count;

Count number of documents this cursor can return. You can also append a callback to perform operation non-blocking.

  $cursor->count(sub {
    my ($cursor, $err, $count) = @_;
    ...
  });
  Mojo::IOLoop->start unless Mojo::IOLoop->is_running;

  my $values = $cursor->distinct('foo');

Get all distinct values for key. You can also append a callback to perform operation non-blocking.

  $cursor->distinct(foo => sub {
    my ($cursor, $err, $values) = @_;
    ...
  });
  Mojo::IOLoop->start unless Mojo::IOLoop->is_running;

  my $doc = $cursor->explain;

Provide information on the query plan. You can also append a callback to perform operation non-blocking.

  $cursor->explain(sub {
    my ($cursor, $err, $doc) = @_;
    ...
  });
  Mojo::IOLoop->start unless Mojo::IOLoop->is_running;