NAME

DBIx::Lite - Chained and minimal ORM

VERSION

version 0.36

SYNOPSIS

    use DBIx::Lite;
    
    my $dbix = DBIx::Lite->new(driver_name => 'Pg');  # disconnected mode
    my $dbix = DBIx::Lite->new(dbh => $dbh);
    my $dbix = DBIx::Lite->connect("dbi:Pg:dbname=$db", $user, $passwd, {pg_enable_utf8 => 1});
    
    # build queries using chained methods -- no schema definition required
    my $authors_rs = $dbix->table('authors');
    my $authors_rs = $dbix->table('authors')->search({ country => 'IT' });
    my $books_rs = $dbix
        ->table('books')
        ->select('id', 'title', 'year')
        ->left_join('authors', { author_id => 'id' })
        ->select_also(['authors.name' => 'author_name'])
        ->order_by('year');
    
    # retrieve rows and columns -- still no schema definition required
    my @authors = $authors_rs->all;
    my $author = $authors_rs->search({ id => 1 })->single;
    while (my $book = $books_rs->next) {
        printf "%s (%s)\n", $book->title, $book->author_name;  # automatic accessor methods
    }
    my @author_names = $authors_rs->get_column('name');
    my $book_count = $books_rs->count;
    
    # manipulate rows
    my $book = $dbix->table('books')->insert({ name => 'Camel Tales', year => 2012 });
    $books_rs->search({ year => { '<' => 1920 } })->update({ very_old => 1 });
    $authors_rs->search({ age => { '>' => 99 } })->delete;
    
    # define a primary key and get more features
    $dbix->schema->table('authors')->autopk('id');
    my $author = $dbix_lite->table('authors')->find(2);
    $author->update({ age => 40 });
    $author->delete;
    
    # define relationships
    $dbix->schema->one_to_many('authors.id' => 'books.author_id', 'author');
    my $author = $books->author;
    my $books_rs = $author->books->search({ year => 2012 });
    my $book = $author->insert_related('books', { title => "A Camel's Life" });
    
    # define custom object classes
    $dbix->schema
        ->table('subjects')
        ->class('My::Subject')
        ->resultset_class('My::Subject::ResultSet');

ABSTRACT

Many ORMs and DBI abstraction layers are available on CPAN, one of the most notables being DBIx::Class which provides the most powerful features to handle database contents using OOP.

DBIx::Lite was written with some goals in mind, that no other available module provides. Such goals/key features are:

no need to define your database schema (most features work without one and some advanced features only require some bits, and still not the full table definitions)
no need to connect to database: the module can just generate SQL for you
chained methods with lazy SQL generation
joins/relationships
optional custom classes for results and resultsets with custom methods
SQL::Abstract syntax
paging features (with Data::Page)

METHODS

Instantiating a DBIx::Lite object isn't more difficult than just writing:

    my $dbix = DBIx::Lite->new(driver_name => 'Pg');

Driver name is the name of the DBI module you expect to use. We need to specify it as the generated SQL will depend on the driver. This constructor will give you an unconnected object, that you can use to generate SQL commands using the select_sql(), insert_sql(), update_sql() and delete_sql() methods without executing it.

If you want to connect to a database you can pass a pre-connected database handle with the "dbh" argument or you can supply your connection options to the connect() method. All arguments passed to connect() will be just passed to DBIx::Connector which will be used to manage your connection under the hood.

    my $dbix = DBIx::Lite->new(dbh => $dbh);
    my $dbix = DBIx::Lite->connect("dbi:Pg:dbname=$db", $user, $passwd, {pg_enable_utf8 => 1});

Note that connect() can be called as an object method too, if you want to connect an unconnected DBIx::Lite object at a later stage:

    my $dbix = DBIx::Lite->new;
    $dbix->connect("dbi:Pg:dbname=$db", $user, $passwd);

new

This class method may accept the following optional arguments:

dbh

This argument allows you to supply a pre-made DBI database handle. See the example in the previous paragraph.

connector

This argument allows you to supply a pre-made DBIx::Connector object.

schema

This argument allows you to supply a pre-made DBIx::Lite::Schema object. If none is provided, a new empty one will be created for each DBIx::Lite object. This argument is useful if you want to prepare your schema in advance and reutilize it across multiple connections.

abstract

This argument allows you to supply options for SQL::Abstract::More module. Here is example for MySQL DB backend to quote fields names with backtick to allow using reserved words as column's names.

    my $dbix = DBIx::Lite->new( abstract => { quote_char => '`', name_sep => '.' } );
    $dbix->connect("DBI:mysql:$db_dbname;host=$db_host", $db_username, $db_password);

connect

This methods accepts a list of arguments that are passed to DBIx::Connector. It returns the DBIx::Lite object. It can be called either as class or object method.

table

This method accepts a table name and returns a DBIx::Lite::ResultSet object on which you can chain its methods to build your query.

    my $rs = $dbix->table('books');

schema

This method returns our DBIx::Lite::Schema object which may hold the definitions required for some advanced feature of DBIx::Lite. You can call then call its methods:

    $dbix->schema->table('authors')->autopk('id');

See the DBIx::Lite::Schema documentation for an explanation of its methods.

dbh

This method returns a DBI database handle that you can use to perform manual queries.

txn

This method accepts a coderef which will be run inside a transaction.

    $dbix->txn(sub {
        $dbix->table('books')->update({ year => 2015 });
    });

AUTHOR

Alessandro Ranellucci <aar@cpan.org>

COPYRIGHT AND LICENSE

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.