Alexander Ponomarev > ActiveRecord-Simple > ActiveRecord::Simple

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NAME ^

ActiveRecord::Simple - Simple to use lightweight implementation of ActiveRecord pattern.

VERSION ^

Version 0.53

NAME ^

ActiveRecord::Simple

VERSION ^

0.53

DESCRIPTION ^

ActiveRecord::Simple is a simple lightweight implementation of ActiveRecord pattern. It's fast, very simple and very light.

SYNOPSIS ^

    package MyModel:Person;

    use base 'ActiveRecord::Simple';

    __PACKAGE__->table_name('persons');
    __PACKAGE__->columns(['id', 'name']);
    __PACKAGE__->primary_key('id');

    1;

That's it! Now you're ready to use your active-record class in the application:

    use MyModel::Person;

    # to create a new record:
    my $person = MyModel::Person->new({ name => 'Foo' })->save();

    # to update the record:
    $person->name('Bar')->save();

    # to get the record (using primary key):
    my $person = MyModel::Person->get(1);

    # to get the record with specified fields:
    my $person = MyModel::Person->find(1)->only('name', 'age')->fetch;

    # to find records by parameters:
    my @persons = MyModel::Person->find({ name => 'Foo' })->fetch();

    # to find records by sql-condition:
    my @persons = MyModel::Person->find('name = ?', 'Foo')->fetch();

    # also you can do something like this:
    my $persons = MyModel::Person->find('name = ?', 'Foo');
    while ( my $person = $persons->fetch() ) {
        say $person->name;
    }

    # You can add any relationships to your tables:
    __PACKAGE__->relations({
        cars => {
            class => 'MyModel::Car',
            key   => 'id_person',
            type  => 'many',
        },
        wife => {
            class => 'MyModel::Wife',
            key   => 'id_person',
            type  => 'one',
        }
    });

    # And then, you're ready to go:
    say $person->cars->fetch->id; # if the relation is one to many
    say $person->wife->name; # if the relation is one to one
    $person->wife(Wife->new({ name => 'Jane', age => '18' })->save)->save; # change wife ;-)

METHODS ^

ActiveRecord::Simple provides a variety of techniques to make your work with data little easier. It contains only a basic set of operations, such as search, create, update and delete data.

If you realy need more complicated solution, just try to expand on it with your own methods.

Class Methods ^

Class methods mean that you can't do something with a separate row of the table, but they need to manipulate of the table as a whole object. You may find a row in the table or keep database handler etc.

new

Creates a new object, one row of the data.

    MyModel::Person->new({ name => 'Foo', second_name => 'Bar' });

It's a constructor of your class and it doesn't save a data in the database, just creates a new record in memory.

columns

    __PACKAGE__->columns([qw/id_person first_name second_name]);

Set names of the table columns and add accessors to object of the class. This method is required to use in the child (your model) classes.

primary_key

    __PACKAGE__->primary_key('id_person');

Set name of the primary key. This method is not required to use in the child (your model) classes.

table_name

    __PACKAGE__->table_name('persons');

Set name of the table. This method is required to use in the child (your model) classes.

relations

    __PACKAGE__->relations({
        cars => {
            class => 'MyModel::Car',
            key   => 'id_person',
            type  => 'many'
        },
    });

It's not a required method and you don't have to use it if you don't want to use any relationships in your tables and objects. However, if you need to, just keep this simple schema in youre mind:

    __PACKAGE__->relations({
        [relation key] => {
            class => [class name],
            key   => [column that refferers to the table],
            type  => [many or one]
        },
    })

    [relation key] - this is a key that will be provide the access to instance
    of the another class (which is specified in the option "class" below),
    associated with this relationship. Allowed to use as many keys as you need:

    $package_instance->[relation key]->[any method from the related class];

use_smart_saving

This method provides two features:

   1. Check the changes of object's data before saving in the database.
      Won't save if data didn't change.

   2. Automatic save on object destroy (You don't need use "save()" method
      anymore).

    __PACKAGE__->use_smart_saving;

find

There are several ways to find someone in your database using ActiveRecord::Simple:

    # by "nothing"
    # just leave attributes blank to recieve all rows from the database:
    my @all_persons = MyModel::Person->find()->fetch;

    # by primary key:
    my $person = MyModel::Person->find(1)->fetch;

    # by multiple primary keys
    my @persons = MyModel::Person->find([1, 2, 5])->fetch;

    # by simple condition:
    my @persons = MyModel::Person->find({ name => 'Foo' })->fetch;

    # by where-condtions:
    my @persons = MyModel::Person->find('first_name = ? and id_person > ?', 'Foo', 1);

If you want to get a few instances by primary keys, you should put it as arrayref, and then fetch from resultset:

    my @persons = MyModel::Person->find([1, 2])->fetch();

    # you don't have to fetch it immidiatly, of course:
    my $resultset = MyModel::Person->find([1, 2]);
    while ( my $person = $resultset->fetch() ) {
        say $person->first_name;
    }

To find some rows by simple condition, use a hashref:

    my @persons = MyModel::Person->find({ first_name => 'Foo' })->fetch();

Simple condition means that you can use only this type of it:

    { first_name => 'Foo' } goes to "first_type = 'Foo'";
    { first_name => 'Foo', id_person => 1 } goes to "first_type = 'Foo' and id_person = 1";

If you want to use a real sql where-condition:

    my $res = MyModel::Person->find('first_name = ? or id_person > ?', 'Foo', 1);
    # select * from persons where first_name = "Foo" or id_person > 1;

You can use the ordering of results, such as ORDER BY, ASC and DESC:

    my @persons = MyModel::Person->find('age > ?', 21)->order_by('name')->desc->fetch();
    my @persons = MyModel::Person->find('age > ?', 21)->order_by('name', 'age')->fetch();

count

Returns count of records that match the rule:

    say MyModel::Person->count;
    say MyModel::Person->count({ zip => '12345' });
    say MyModel::Person->count('age > ?', 55);

exists

Returns 1 if record is exists in database:

    say "Exists" if MyModel::Person->exists({ zip => '12345' });
    say "Exists" if MyModel::Person->exists('age > ?', 55);

first

Returns the first record (records) ordered by the primary key:

    my $first_person = MyModel::Person->first->fetch;
    my @ten_persons  = MyModel::Person->first(10)->fetch;

last

Returns the last record (records) ordered by the primary key:

    my $last_person = MyModel::Person->last->fetch;
    my @ten_persons = MyModel::Person->last(10)->fetch;

increment

Increment the field value:

    my $person = MyModel::Person->get(1);
    say $person->age;  # prints e.g. 99
    $person->increment('age');
    say $person->age; # prints 100

decrement

Decrement the field value:

    my $person = MyModel::Person->get(1);
    say $person->age;  # prints e.g. 100
    $person->decrement('age');
    say $person->age; # prints 99

dbh

Keeps a database connection handler. It's not a class method actually, this is an attribute of the base class and you can put your database handler in any class:

    Person->dbh($dbh);

Or even rigth in base class:

    ActiveRecord::Simple->dbh($dht);

This decision is up to you. Anyway, this is a singleton value, and keeps only once at the session.

Object Methods ^

Object methods usefull to manipulating single rows as a separate objects.

only

Get only those fields that are needed:

    my $person = MyModel::Person->find({ name => 'Alex' })->only('address', 'email')->fetch;
    ### SQL:
    ###     SELECT `address`, `email` from `persons` where `name` = "Alex";

get

This is shortcut method for "find":

    my $person = MyModel::Person->get(1);
    ### is the same:
    my $person = MyModel::Person->find(1)->fetch;

order_by

Order your results by specified fields:

    my @persons = MyModel::Person->find({ city => 'NY' })->order_by('name')->fetch();

This method uses as many fields as you want:

    my @fields = ('name', 'age', 'zip');
    my @persons = MyModel::Person->find({ city => 'NY' })->order_by(@fields)->fetch();

asc

Use this attribute to order your results ascending:

    MyModel::Person->find([1, 3, 5, 2])->order_by('id')->asc->fetch();

desc

Use this attribute to order your results descending:

    MyModel::Person->find([1, 3, 5, 2])->order_by('id')->desc->fetch();

limit

Use this attribute to limit results of your requests:

    MyModel::Person->find()->limit(10)->fetch; # select only 10 rows

offset

Offset of results:

    MyModel::Person->find()->offset(10)->fetch; # all next after 10 rows

save

To insert or update data in the table, use only one method. It detects automatically what do you want to do with it. If your object was created by the new method and never has been saved before, method will insert your data.

If you took the object using the find method, "save" will mean "update".

    my $person = MyModel::Person->new({
        first_name => 'Foo',
        secnd_name => 'Bar',
    });

    $person->save() # -> insert

    $person->first_name('Baz');
    $person->save() # -> now it's update!

    ### or

    my $person = MyModel::Person->find(1);
    $person->first_name('Baz');
    $person->save() # update

delete

    $person->delete();

Delete row from the table.

exists

Checks for a record in the database corresponding to the object:

    my $person = MyModel::Person->new({
        first_name => 'Foo',
        secnd_name => 'Bar',
    });

    $person->save() unless $person->exists;

to_hash

Convert objects data to the simple perl hash:

    use JSON::XS;

    say encode_json({ person => $peron->to_hash });

is_defined

Checks weather an object is defined:

    my $person = MyModel::Person->find(1);
    return unless $person->is_defined;

fetch

When you use the "find" method to get a few rows from the table, you get the meta-object with a several objects inside. To use all of them or only a part, use the "fetch" method:

    my @persons = MyModel::Person->find('id_person != ?', 1)->fetch();

You can also specify how many objects you want to use at a time:

    my @persons = MyModel::Person->find('id_person != ?', 1)->fetch(2);
    # fetching only 2 objects.

Another syntax of command "fetch" allows you to make read-only objects:

    my @persons = MyModel::Person->find->fetch({ read_only => 1, limit => 2 });
    # all two object are read-only

TRACING QUERIES ^

   use ACTIVE_RECORD_SIMPLE_TRACE=1 environment variable:

   $ ACTIVE_RECORD_SIMPLE_TRACE=1 perl myscript.pl

SEE ALSO ^

    DBIx::ActiveRecord

MORE INFO ^

    perldoc ActiveRecord::Simple::Tutorial

AUTHOR ^

shootnix, <shootnix at cpan.org>

BUGS ^

Please report any bugs or feature requests to shootnix@cpan.org, or through the github: https://github.com/shootnix/activerecord-simple/issues

SUPPORT ^

You can find documentation for this module with the perldoc command.

    perldoc ActiveRecord::Simple

You can also look for information at:

ACKNOWLEDGEMENTS ^

LICENSE AND COPYRIGHT ^

Copyright 2013 shootnix.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.

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