NAME

CPAN::Search::Lite::Query - perform queries on the database

SYNOPSIS

my $max_results = 200;
my $query = CPAN::Search::Lite::Query->new(db => $db,
                                           user => $user,
                                           passwd => $passwd,
                                           max_results => $max_results);
$query->query(mode => 'module', name => 'Net::FTP');
my $results = $query->{results};

CONSTRUCTING THE QUERY

This module queries the database via various types of queries and returns the results for subsequent display. The CPAN::Search::Lite::Query object is created via the new method as

my $query = CPAN::Search::Lite::Query->new(db => $db,
                                           user => $user,
                                           passwd => $passwd,
                                           max_results => $max_results);

which takes as arguments

• db => $db

  This is the name of the database.

• user => $user

  This is the user under which the database connection will be made.

• passwd => $passwd

  This is the password to use when connecting.

• max_results => $max_results

  This is the maximum value used to limit the number of results returned under a user query. If not specified, a value contained within CPAN::Search::Lite::Query will be used.

A basic query then is constructed as

$query->query(mode => $mode, $type => $value);

with the results available as

my $results = $query->{results}

There are four basic modes:

• module

  This is for information on modules.

• dist

  This is for information on distributions.

• author

  This is for information on CPAN authors or cpanids.

• chapter

  This is for information on chapters associated with distributions and modules.

module, dist, and author modes

For a mode of module, dist, and author, there are four basic options to be used for the $type => $value option:

• query => $query_term

  This will search through module names and abstracts, distribution names and abstracts, or CPAN author names and full names (for module, dist, and author modes respectively). The results generally are case insensitive. Matches are reported that match all search terms supplied - for example, $query_term = 'foo bar' will find occurences of foo and bar. To exclude a term in $query_term, prepend that term with a minus sign = $query_term = 'foo -bar' will find all instances foo that don't include bar. Regular expressions (as used by mysql) are also supported.

• name => $name

  This will report exact matches (in a case sensitive manner) for the module name, distribution name, or CPAN author id, for module, dist, and author modes respectively.

• letter => $letter

  If $letter is a single letter, this will find all modules, distributions, or CPAN author ids beginning with that letter (for module, dist, and author modes respectively). If $letter is more than one letter, this will find all distribtion names matching $letter-* (for the dist mode) or all module names matching $letter::* (for the module mode).

• id => $id

  This will look up information on the primary key according to the mode specified. This is more for internal use, to help speed up queries; using this "publically" is probably not a good idea, as the ids may change over the course of time.

As well, for the dist mode there is an additional type: recent => $age, which will report all distribtions uploaded in the last $age days. If $age is not specified, it will default to 7.

chapter mode

For a mode of chapter, one can specify two additional arguments:

• id => $chapterid

  This argument (which is required) will look up all subchapters with the specified numerical $chapterid (see %chaps of CPAN::Search::Lite::Util for a description).

• subchapter => $subchapter

  This argument (which is optional) will look up all distributions with the specified $subchapter within the given chapter specified by $chapterid.

RESULTS

After making the query, the results can be accessed through

my $results = $query->{results};

No results either can mean no matches were found, or else an error in making the query resulted (in which case, a brief error message is contained in $query->{error}). Assuming there are results, what is returned depends on the mode and on the type of query. See CPAN::Search::Lite::Populate for a description of the fields in the various tables listed below - these fields are used as the keys of the hash references that arise.

author mode

• name or id query

  This returns the auth_id, cpanid, email, and fullname of the auths table. As well, an array reference $results->{dists} is returned representing all distributions associated with that cpanid - each member of the array reference is a hash reference describing the dist_id, dist_name, birth, dist_abs, dist_vers, and dist_file fields in the dists table. An additional entry, download, is supplied, which can be used as $CPAN/authors/id/$download to specify the url of the distribution.

• letter query

  This returns an array reference, each member of which is a hash reference containing the auth_id, cpanid, and fullname fields.

• query query

  If this results in more than one match, an array reference is returned, each member of which is a hash reference containg the auth_id, cpanid, and fullname fields. If there is only one result found, a name query based on the matched cpanid is performed.

module mode

• name or id query

  This returns the mod_id, mod_name, mod_abs, doc, mod_vers, dslip, chapterid, dist_id, dist_name, dist_file, auth_id, cpanid, and fullname of the auths, mods, and dists tables. As well, the following entries may be present.

  • html

    If doc is true, an entry html is constructed giving the location (relative to html_root) of the html file.

  • download

    This can be used as $CPAN/authors/id/$download to specify the url of the distribution.

  • chap_desc

    An accompanying entry chap_desc is supplied giving a description of chapterid, if present.

  • dslip_info

    If dslip is available, an array reference dslip_info is supplied, each entry being a hash reference. The hash reference contains two keys - desc, whose value is a general description of the what the dslip entry represents, and what, whose value is a description of the entry itself.

  • ppms

    If there are ppm packages available for the distribution containing the module, an array reference ppms is supplied, each item of which is a hash reference. There are three keys in this hash reference (coming from $repositories of CPAN::Search::Lite::Util) - rep_id, giving the repository's rep_id, desc, giving a description of the repository, and browse, giving a url to the repository.

• letter query

  This returns an array reference, each entry of which can be of two types. If there are multiple occurrences of a module matching FOO::* at the top level, then the entry is a hash reference with key letter and associated value FOO. If there is only one module matching FOO::* at the top level, then the entry is a hash reference containing the mod_id, mod_name, and mod_abs fields.

• query query

  If this results in more than one match, an array reference is returned, each member of which is a hash reference containing the mod_id, mod_name, and mod_abs fields. If there is only one result found, a name query based on the matched mod_name is performed.

dist mode

• name or id query

  This returns the dist_id, dist_name, dist_abs, dist_vers, dist_file, size, birth, readme, changes, meta, install, auth_id, cpanid, and fullname of the auths, mods, and dists tables. Note that readme, changes, meta, and install are boolean values just indicating if the corresponding file is present. As well, the following entries may be present.

  • download

    This can be used as $CPAN/authors/id/$download to specify the url of the distribution.

  • mods

    This is an array reference containing information on the modules present. Each entry is a hash reference containing the mod_id, mod_name, mod_abs, mod_vers, doc, and dslip fields for the module. If doc is present, an html entry is created giving the location (relative to html_root) of the documentation.

  • dslip and dslip_info

    If the module name and distribution name are related by s/::/-, the dslip and dslip_info entries for that module are returned.

  • chaps

    If present, an array reference chaps is returned, each entry of which is a hash reference containing chapterid, subchapter, and chap_desc (a description of the chapter id).

  • reqs

    If prerequisites for the distribtion have been specified, an array reference reqs is returned, each item of which is a hash reference containing mod_id, req_vers, mod_name, and mod_abs for each prerequisite.

  • ppms

    If there are ppm packages available for the distribution, an array reference ppms is supplied, each item of which is a hash reference. There are three keys in this hash reference (coming from $repositories of CPAN::Search::Lite::Util) - rep_id, giving the repository's rep_id, desc, giving a description of the repository, and browse, giving a url to the repository.

• letter query

  This returns an array reference, each entry of which can be of two types. If there are multiple occurrences of a distribution matching FOO-* at the top level, then the entry is a hash reference with key letter and associated value FOO. If there is only one distribution matching FOO-* at the top level, then the entry is a hash reference containing the dist_id, dist_name, and dist_abs fields.

• query query

  If this results in more than one match, an array reference is returned, each member of which is a hash reference containing the dist_id, dist_name, and dist_abs fields. If there is only one result found, a name query based on the matched dist_name is performed.

• recent query

  This performs a query for all distributions uploaded to CPAN in the last 7 days. The result is an array reference, each item of which is a hash reference containing the birth, dist_id, dist_name, dist_abs, dist_vers, dist_file, auth_id, and cpanid fields. As well, for each entry a download entry is present, which can be used as $CPAN/authors/id/$download to specify the url of the distribution.

chapter mode

• id => $chapterid

  This will return an array reference, each item of which is a hash reference containing the corresponding subchapter field.

• subchapter => $subchapter

  This will return an array reference corresponding to all distributions with the specified subchapter within the given chapter. Each item of the array reference is a hash reference specifying the dist_id, dist_name, and dist_abs of the distribution.

For a name or id query of dist, author, or module, if the query is constructed as

$query->query(mode => $mode, $type => $value, fields => $fields);

where $fields is an array reference, then only those fields specified will be returned. For author, only the auths table is searched, for module, the mods, auths, and dists tables are searched, and for dist, the dists and auths tables are searched.

SEE ALSO

Apache::CPAN::Search and Apache::CPAN::Query.

COPYRIGHT

This software is copyright 2004 by Randy Kobes <randy@theoryx5.uwinnipeg.ca>. Use and redistribution are under the same terms as Perl itself.

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