NAME
    Mad::Mapper - Map Perl objects to PostgreSQL, MySQL or SQLite data

VERSION
    0.09

DESCRIPTION
    Mad::Mapper is a base class for objects that should be stored in a
    persistent SQL database. Currently the supported backends are Mojo::Pg
    Mojo::mysql and Mojo::SQLite. These backends need to be installed
    separately.

      $ cpanm Mad::Mapper
      $ cpanm Mojo::Pg # Mad::Mapper now supports postgres!

    THIS MODULE IS EXPERIMENTAL. It is in use in production though, so big
    changes will not be made without extreme consideration.

SYNOPSIS
      package MyApp::Model::User;
      use Mad::Mapper -base;

      # Class attributes
      col id => undef;
      col email => '';

    See also Mad::Mapper::Guides::Tutorial for more details and
    Mad::Mapper::Guides::Custom if you want more control.

RELATIONSHIPS
    See Mad::Mapper::Guides::HasMany for example "has many" relationship.

    TODO: "belongs_to()" and maybe "has_one()".

EXPORTED FUNCTIONS
  col
    Used to define a column. Follow the same rules as "has".

  has
      has name => "Bruce";
      has [qw(name email)];
      has pet => sub { Cat->new };

    Same as "has" in Mojo::Base.

  pk
    Used to define a primary key. Follow the same rules as "has".

    The primary key is used by default in "load" and "update" to update the
    correct row. If omitted, the first "col" will act as primary key.

    Note that "pk" is not returned by "columns".

  table
    Used to define a table name. The default is to decamelize the last part
    of the class name and add "s" at the end, unless it already has "s" at
    the end. Examples:

      .-------------------------------------.
      | Class name            | table       |
      |-----------------------|-------------|
      | App::Model::User      | users       |
      | App::Model::Users     | users       |
      | App::Model::Group     | groups      |
      | App::Model::UserAgent | user_agents |
      '-------------------------------------'

ATTRIBUTES
  db
      $db = $self->db;
      $self->db($db_obj);

    Need to hold either a Mojo::Pg::Database or Mojo::mysql::Database
    object.

  in_storage
      $bool = $self->in_storage;
      $self = $self->in_storage($bool);

METHODS
  expand_sql
      ($sql, @args) = $self->expand_sql($sql, @args);

    Used to expand a given $sql statement with variables defined by helpers.

    *   %t

        Will be replaced by "table". Example: "SELECT * FROM %t" becomes
        "SELECT * FROM users".

    *   %c

        Will be replaced by "columns". Example: "name,email".

    *   %c=

        Will be replaced by "columns" assignment. Example: "name=?,email=?"

    *   %c?

        Will be replaced by "columns" placeholders. Example: "?,?,?"

    *   %pc

        Include "pk" in list of columns. Example: "id,name,email".

    *   \%c

        Becomes a literal "%c".

    It is also possible to define aliases for "%t", "%c", "%c=" and "%pc".
    Example:

      %t.x = some_table as x
      %c.x = x.col1

  expand_sst
    DEPRECATED in favor of "expand_sql".

  columns
      @str = $self->columns;

    Returns a list of columns, defined by "col".

  delete
      $self = $self->delete;
      $self = $self->delete(sub { my ($self, $err) = @_, ... });

    Will delete the object from database if "in_storage".

  fresh
      $self = $self->fresh;

    Will mark the next relationship accessor to fetch new data from
    database, instead of using the cached data on $self.

  load
      $self = $self->load;
      $self = $class->load(sub { my ($self, $err) = @_; });

    Used to fetch data from storage and update the object attributes.

  save
      $self = $self->save;
      $self = $self->save(sub { my ($self, $err) = @_, ... });

    Will update the object in database if "in_storage" or insert it if not.

  import
    Will set up the caller class with Mad::Mapper functionality if "-base"
    is given as argument. See "SYNOPSIS" for example.

COPYRIGHT AND LICENSE
    Copyright (C) 2014-2016, Jan Henning Thorsen

    This program is free software, you can redistribute it and/or modify it
    under the terms of the Artistic License version 2.0.

AUTHOR
    Jan Henning Thorsen - "jhthorsen@cpan.org"

    Красимир Беров - "berov@cpan.org"

    Stefan Adams - "sadams@cpan.org"