Welcome to Paris’s documentation!¶
Contents:
Installation¶
Packagist¶
This library is available through Packagist with the vendor and package
identifier of j4mie/paris
Please see the Packagist documentation for further information.
Download¶
You can clone the git repository, download idiorm.php or a release tag and then drop the idiorm.php file in the vendors/3rd party/libs directory of your project.
Configuration¶
Setup¶
Paris requires Idiorm. Install Idiorm and Paris somewhere in your
project directory, and require
both.
<?php
require_once 'your/path/to/idiorm.php';
require_once 'your/path/to/paris.php';
Then, you need to tell Idiorm how to connect to your database. For full details of how to do this, see `Idiorm’s documentation`_.
Briefly, you need to pass a Data Source Name connection string to the
configure
method of the ORM class.
<?php
ORM::configure('sqlite:./example.db');
You may also need to pass a username and password to your database
driver, using the username
and password
configuration options.
For example, if you are using MySQL:
<?php
ORM::configure('mysql:host=localhost;dbname=my_database');
ORM::configure('username', 'database_user');
ORM::configure('password', 'top_secret');
Model prefixing¶
Setting: Model::$auto_prefix_models
To save having type out model class name prefixes whenever code utilises Model::for_table()
it is possible to specify a prefix that will be prepended onto the class name.
The model prefix is treated the same way as any other class name when Paris attempts to convert it to a table name. This is documented in the Models section of the documentation.
Here is a namespaced example to make it clearer:
<?php
Model::$auto_prefix_models = '\\Tests\\';
Model::factory('Simple')->find_many(); // SQL executed: SELECT * FROM `tests_simple`
Model::factory('SimpleUser')->find_many(); // SQL executed: SELECT * FROM `tests_simple_user`
Model prefixes are only compatible with the Model::factory()
methods described above.
Where the shorter SimpleUser::find_many()
style syntax is used, the addition of a
Model prefix will cause Class not found
errors.
Note
Model class property $_table
sets an explicit table name, ignoring the
$auto_prefix_models
property in your individual model classes. See documentation in
the Models section of the documentation.
Model prefixing¶
Setting: Model::$short_table_names
Set as true
to disregard namespace information when computing table names
from class names.
By default the class \Models\CarTyre
expects the table name models_car_tyre
.
With Model::$short_table_names = true
the class \Models\CarTyre
expects the
table name car_tyre
.
<?php
Model::$short_table_names = true;
Model::factory('CarTyre')->find_many(); // SQL executed: SELECT * FROM `car_tyre`
namespace Models {
class CarTyre extends Model {
}
}
Further Configuration¶
The only other configuration options provided by Paris itself are the
$_table
and $_id_column
static properties on model classes. To
configure the database connection, you should use Idiorm’s configuration
system via the ORM::configure
method.
If you are using multiple connections, the optional $_connection_key static property may also be used to provide a default string key indicating which database connection in ORM should be used.
See `Idiorm’s documentation`_ for full details.
Query logging¶
Idiorm can log all queries it executes. To enable query logging, set the
logging
option to true
(it is false
by default).
<?php
ORM::configure('logging', true);
When query logging is enabled, you can use two static methods to access
the log. ORM::get_last_query()
returns the most recent query
executed. ORM::get_query_log()
returns an array of all queries
executed.
Models¶
Model classes¶
You should create a model class for each entity in your application. For
example, if you are building an application that requires users, you
should create a User
class. Your model classes should extend the
base Model
class:
<?php
class User extends Model {
}
Paris takes care of creating instances of your model classes, and populating them with data from the database. You can then add behaviour to this class in the form of public methods which implement your application logic. This combination of data and behaviour is the essence of the Active Record pattern.
IDE Auto-complete¶
As Paris does not require you to specify a method/function per database column it can be difficult to know what properties are available on a particular model. Due to the magic nature of PHP’s `__get()`_ method it is impossible for an IDE to give you autocomplete hints as well.
To work around this you can use PHPDoc comment blocks to list the properties of the model. These properties should mirror the names of your database tables columns.
<?php
/**
* @property int $id
* @property string $first_name
* @property string $last_name
* @property string $email
*/
class User extends Model {
}
For more information please see the PHPDoc manual @property documentation.
Database tables¶
Your User
class should have a corresponding user
table in your
database to store its data.
By default, Paris assumes your class names are in CapWords style, and
your table names are in lowercase_with_underscores style. It will
convert between the two automatically. For example, if your class is
called CarTyre
, Paris will look for a table named car_tyre
.
If you are using namespaces then they will be converted to a table name
in a similar way. For example \Models\CarTyre
would be converted to
models_car_tyre
. Note here that backslashes are replaced with underscores
in addition to the CapWords replacement discussed in the previous paragraph.
To disregard namespace information when calculating the table name, set
Model::$short_table_names = true;
. Optionally this may be set or overridden at
class level with the public static property $_table_use_short_name
. The
$_table_use_short_name
takes precedence over Model::$short_table_names
unless $_table_use_short_name
is null
(default).
Either setting results in \Models\CarTyre
being converted to car_tyre
.
<?php
class User extends Model {
public static $_table_use_short_name = true;
}
To override the default naming behaviour and directly specify a table name,
add a public static property to your class called $_table
:
<?php
class User extends Model {
public static $_table = 'my_user_table';
}
Auto prefixing¶
To save having type out model class name prefixes whenever code utilises Model::for_table()
it is possible to specify a prefix that will be prepended onto the class name.
See the Configuration documentation for more details.
ID column¶
Paris requires that your database tables have a unique primary key
column. By default, Paris will use a column called id
. To override
this default behaviour, add a public static property to your class
called $_id_column
:
<?php
class User extends Model {
public static $_id_column = 'my_id_column';
}
Note - Paris has its own default ID column name mechanism, and does not respect column names specified in Idiorm’s configuration.
Associations¶
Paris provides a simple API for one-to-one, one-to-many and many-to-many relationships (associations) between models. It takes a different approach to many other ORMs, which use associative arrays to add configuration metadata about relationships to model classes. These arrays can often be deeply nested and complex, and are therefore quite error-prone.
Instead, Paris treats the act of querying across a relationship as a behaviour, and supplies a family of helper methods to help generate such queries. These helper methods should be called from within methods on your model classes which are named to describe the relationship. These methods return ORM instances (rather than actual Model instances) and so, if necessary, the relationship query can be modified and added to before it is run.
Summary¶
The following list summarises the associations provided by Paris, and explains which helper method supports each type of association:
One-to-one¶
Use has_one
in the base, and belongs_to
in the associated model.
One-to-many¶
Use has_many
in the base, and belongs_to
in the associated
model.
Many-to-many¶
Use has_many_through
in both the base and associated models.
Below, each association helper method is discussed in detail.
Has-one¶
One-to-one relationships are implemented using the has_one
method.
For example, say we have a User
model. Each user has a single
Profile
, and so the user
table should be associated with the
profile
table. To be able to find the profile for a particular user,
we should add a method called profile
to the User
class (note
that the method name here is arbitrary, but should describe the
relationship). This method calls the protected has_one
method
provided by Paris, passing in the class name of the related object. The
profile
method should return an ORM instance ready for (optional)
further filtering.
<?php
class Profile extends Model {
}
class User extends Model {
public function profile() {
return $this->has_one('Profile');
}
}
The API for this method works as follows:
<?php
// Select a particular user from the database
$user = Model::factory('User')->find_one($user_id);
// Find the profile associated with the user
$profile = $user->profile()->find_one();
By default, Paris assumes that the foreign key column on the related
table has the same name as the current (base) table, with _id
appended. In the example above, Paris will look for a foreign key column
called user_id
on the table used by the Profile
class. To
override this behaviour, add a second argument to your has_one
call,
passing the name of the column to use.
- In addition, Paris assumes that the foreign key column in the current (base)
- table is the primary key column of the base table. In the example above,
Paris will use the column called user_id
(assuming user_id
is the
primary key for the user table) in the base table (in this case the user table)
as the foreign key column in the base table. To override this behaviour,
add a third argument to your has_one call
, passing the name of the column
you intend to use as the foreign key column in the base table.
Has many¶
One-to-many relationships are implemented using the has_many
method.
For example, say we have a User
model. Each user has several
Post
objects. The user
table should be associated with the
post
table. To be able to find the posts for a particular user, we
should add a method called posts
to the User
class (note that
the method name here is arbitrary, but should describe the
relationship). This method calls the protected has_many
method
provided by Paris, passing in the class name of the related objects.
Pass the model class name literally, not a pluralised version. The
posts
method should return an ORM instance ready for (optional)
further filtering.
<?php
class Post extends Model {
}
class User extends Model {
public function posts() {
return $this->has_many('Post'); // Note we use the model name literally - not a pluralised version
}
}
The API for this method works as follows:
<?php
// Select a particular user from the database
$user = Model::factory('User')->find_one($user_id);
// Find the posts associated with the user
$posts = $user->posts()->find_many();
By default, Paris assumes that the foreign key column on the related
table has the same name as the current (base) table, with _id
appended. In the example above, Paris will look for a foreign key column
called user_id
on the table used by the Post
class. To override
this behaviour, add a second argument to your has_many
call, passing
the name of the column to use.
In addition, Paris assumes that the foreign key column in the current (base)
table is the primary key column of the base table. In the example above, Paris
will use the column called user_id
(assuming user_id
is the primary key
for the user table) in the base table (in this case the user table) as the
foreign key column in the base table. To override this behaviour, add a third
argument to your has_many call
, passing the name of the column you intend
to use as the foreign key column in the base table.
Belongs to¶
The ‘other side’ of has_one
and has_many
is belongs_to
. This
method call takes identical parameters as these methods, but assumes the
foreign key is on the current (base) table, not the related table.
<?php
class Profile extends Model {
public function user() {
return $this->belongs_to('User');
}
}
class User extends Model {
}
The API for this method works as follows:
<?php
// Select a particular profile from the database
$profile = Model::factory('Profile')->find_one($profile_id);
// Find the user associated with the profile
$user = $profile->user()->find_one();
Again, Paris makes an assumption that the foreign key on the current
(base) table has the same name as the related table with _id
appended. In the example above, Paris will look for a column named
user_id
. To override this behaviour, pass a second argument to the
belongs_to
method, specifying the name of the column on the current
(base) table to use.
Paris also makes an assumption that the foreign key in the associated (related)
table is the primary key column of the related table. In the example above,
Paris will look for a column named user_id
in the user table (the related
table in this example). To override this behaviour, pass a third argument to
the belongs_to method, specifying the name of the column in the related table
to use as the foreign key column in the related table.
Has many through¶
Many-to-many relationships are implemented using the
has_many_through
method. This method has only one required argument:
the name of the related model. Supplying further arguments allows us to
override default behaviour of the method.
For example, say we have a Book
model. Each Book
may have
several Author
objects, and each Author
may have written several
Books
. To be able to find the authors for a particular book, we
should first create an intermediary model. The name for this model
should be constructed by concatenating the names of the two related
classes, in alphabetical order. In this case, our classes are called
Author
and Book
, so the intermediate model should be called
AuthorBook
.
We should then add a method called authors
to the Book
class
(note that the method name here is arbitrary, but should describe the
relationship). This method calls the protected has_many_through
method provided by Paris, passing in the class name of the related
objects. Pass the model class name literally, not a pluralised
version. The authors
method should return an ORM instance ready
for (optional) further filtering.
<?php
class Author extends Model {
public function books() {
return $this->has_many_through('Book');
}
}
class Book extends Model {
public function authors() {
return $this->has_many_through('Author');
}
}
class AuthorBook extends Model {
}
The API for this method works as follows:
<?php
// Select a particular book from the database
$book = Model::factory('Book')->find_one($book_id);
// Find the authors associated with the book
$authors = $book->authors()->find_many();
// Get the first author
$first_author = $authors[0];
// Find all the books written by this author
$first_author_books = $first_author->books()->find_many();
Overriding defaults¶
The has_many_through
method takes up to six arguments, which allow
us to progressively override default assumptions made by the method.
First argument: associated model name - this is mandatory and should be the name of the model we wish to select across the association.
Second argument: intermediate model name - this is optional and defaults to the names of the two associated models, sorted alphabetically and concatenated.
Third argument: custom key to base table on intermediate table -
this is optional, and defaults to the name of the base table with
_id
appended.
Fourth argument: custom key to associated table on intermediate
table - this is optional, and defaults to the name of the associated
table with _id
appended.
Fifth argument: foreign key column in the base table - this is optional, and defaults to the name of the primary key column in the base table.
Sixth argument: foreign key column in the associated table - this is optional, and defaults to the name of the primary key column in the associated table.
Querying¶
Querying allows you to select data from your database and populate
instances of your model classes. Queries start with a call to a static
factory method on the base Model
class that takes a single
argument: the name of the model class you wish to use for your query.
This factory method is then used as the start of a method chain which
gives you full access to Idiorm’s fluent query API. See Idiorm’s
documentation for details of this API.
For example:
<?php
$users = Model::factory('User')
->where('name', 'Fred')
->where_gte('age', 20)
->find_many();
You can also use the same shortcut provided by Idiorm when looking up a record by its primary key ID:
<?php
$user = Model::factory('User')->find_one($id);
If you are using PHP 5.3+ you can also do the following:
<?php
$users = User::where('name', 'Fred')
->where_gte('age', 20)
->find_many();
This does the same as the example above but is shorter and more readable.
The only differences between using Idiorm and using Paris for querying are as follows:
- You do not need to call the
for_table
method to specify the database table to use. Paris will supply this automatically based on the class name (or the$_table
static property, if present). - The
find_one
andfind_many
methods will return instances of your model subclass, instead of the baseORM
class. Like Idiorm,find_one
will return a single instance orfalse
if no rows matched your query, whilefind_many
will return an array of instances, which may be empty if no rows matched. - Custom filtering, see next section.
You may also retrieve a count of the number of rows returned by your
query. This method behaves exactly like Idiorm’s count
method:
<?php
$count = Model::factory('User')->where_lt('age', 20)->count();
A note on PSR-1 and camelCase¶
All the methods detailed in the documentation can also be called in a PSR-1 way: underscores (_) become camelCase. Here follows an example of one query chain being converted to a PSR-1 compliant style.
<?php
// documented and default style
$count = Model::factory('User')->where_lt('age', 20)->find_one();
// PSR-1 compliant style
$count = Model::factory('User')->whereLt('age', 20)->findOne();
As you can see any method can be changed from the documented underscore (_) format to that of a camelCase method name.
Note
In the background the PSR-1 compliant style uses the __call() and __callStatic() magic methods to map the camelCase method name you supply to the original underscore method name. It then uses call_user_func_array() to apply the arguments to the method. If this minimal overhead is too great then you can simply revert to using the underscore methods to avoid it. In general this will not be a bottle neck in any application however and should be considered a micro-optimisation.
As __callStatic() was added in PHP 5.3.0 you will need at least that version of PHP to use this feature in any meaningful way.
Getting data from objects, updating and inserting data¶
The model instances returned by your queries now behave exactly as if
they were instances of Idiorm’s raw ORM
class.
You can access data:
<?php
$user = Model::factory('User')->find_one($id);
echo $user->name;
Update data and save the instance:
<?php
$user = Model::factory('User')->find_one($id);
$user->name = 'Paris';
$user->save();
To create a new (empty) instance, use the create
method:
<?php
$user = Model::factory('User')->create();
$user->name = 'Paris';
$user->save();
To check whether a property has been changed since the object was
created (or last saved), call the is_dirty
method:
<?php
$name_has_changed = $person->is_dirty('name'); // Returns true or false
You can also use database expressions when setting values on your model:
<?php
$user = Model::factory('User')->find_one($id);
$user->name = 'Paris';
$user->set_expr('last_logged_in', 'NOW()');
$user->save();
Of course, because these objects are instances of your base model classes, you can also call methods that you have defined on them:
<?php
class User extends Model {
public function full_name() {
return $this->first_name . ' ' . $this->last_name;
}
}
$user = Model::factory('User')->find_one($id);
echo $user->full_name();
To delete the database row associated with an instance of your model,
call its delete
method:
<?php
$user = Model::factory('User')->find_one($id);
$user->delete();
You can also get the all the data wrapped by a model subclass instance
using the as_array
method. This will return an associative array
mapping column names (keys) to their values.
The as_array
method takes column names as optional arguments. If one
or more of these arguments is supplied, only matching column names will
be returned.
<?php
class Person extends Model {
}
$person = Model::factory('Person')->create();
$person->first_name = 'Fred';
$person->surname = 'Bloggs';
$person->age = 50;
// Returns array('first_name' => 'Fred', 'surname' => 'Bloggs', 'age' => 50)
$data = $person->as_array();
// Returns array('first_name' => 'Fred', 'age' => 50)
$data = $person->as_array('first_name', 'age');
Filters¶
It is often desirable to create reusable queries that can be used to
extract particular subsets of data without repeating large sections of
code. Paris allows this by providing a method called filter
which
can be chained in queries alongside the existing Idiorm query API. The
filter method takes the name of a public static method on the
current Model subclass as an argument. The supplied method will be
called at the point in the chain where filter
is called, and will be
passed the ORM
object as the first parameter. It should return the
ORM object after calling one or more query methods on it. The method
chain can then be continued if necessary.
It is easiest to illustrate this with an example. Imagine an application
in which users can be assigned a role, which controls their access to
certain pieces of functionality. In this situation, you may often wish
to retrieve a list of users with the role ‘admin’. To do this, add a
static method called (for example) admins
to your Model class:
<?php
class User extends Model {
public static function admins($orm) {
return $orm->where('role', 'admin');
}
}
You can then use this filter in your queries:
<?php
$admin_users = Model::factory('User')->filter('admins')->find_many();
You can also chain it with other methods as normal:
<?php
$young_admins = Model::factory('User')
->filter('admins')
->where_lt('age', 18)
->find_many();
Filters with arguments¶
You can also pass arguments to custom filters. Any additional arguments
passed to the filter
method (after the name of the filter to apply)
will be passed through to your custom filter as additional arguments
(after the ORM instance).
For example, let’s say you wish to generalise your role filter (see above) to allow you to retrieve users with any role. You can pass the role name to the filter as an argument:
<?php
class User extends Model {
public static function has_role($orm, $role) {
return $orm->where('role', $role);
}
}
$admin_users = Model::factory('User')->filter('has_role', 'admin')->find_many();
$guest_users = Model::factory('User')->filter('has_role', 'guest')->find_many();
These examples may seem simple (filter('has_role', 'admin')
could
just as easily be achieved using where('role', 'admin')
), but
remember that filters can contain arbitrarily complex code - adding
raw_where
clauses or even complete raw_query
calls to perform
joins, etc. Filters provide a powerful mechanism to hide complexity in
your model’s query API.
Transactions¶
Paris (or Idiorm) doesn’t supply any extra methods to deal with transactions, but it’s very easy to use PDO’s built-in methods:
<?php
// Start a transaction
ORM::get_db()->beginTransaction();
// Commit a transaction
ORM::get_db()->commit();
// Roll back a transaction
ORM::get_db()->rollBack();
For more details, see the PDO documentation on Transactions.
A word on validation¶
It’s generally considered a good idea to centralise your data validation in a single place, and a good place to do this is inside your model classes. This is preferable to handling validation alongside form handling code, for example. Placing validation code inside models means that if you extend your application in the future to update your model via an alternative route (say a REST API rather than a form) you can re-use the same validation code.
Despite this, Paris doesn’t provide any built-in support for validation. This is because validation is potentially quite complex, and often very application-specific. Paris is deliberately quite ignorant about your actual data - it simply executes queries, and gives you the responsibility of making sure the data inside your models is valid and correct. Adding a full validation framework to Paris would probably require more code than Paris itself!
However, there are several simple ways that you could add validation to
your models without any help from Paris. You could override the
save()
method, check the data is valid, and return false
on
failure, or call parent::save()
on success. You could create your
own subclass of the Model
base class and add your own generic
validation methods. Or you could write your own external validation
framework which you pass model instances to for checking. Choose
whichever approach is most suitable for your own requirements.
Migrations¶
Paris does not have native support for migrations, but some work has been done to integrate PHPMig. If you want to have migrations in your project then this is recommended route as Paris will never have migrations directly implemented in the core. Please refer to the Paris and Idiorm Philosophy for reasons why.
To integrate Paris with PHPMig you will need to follow their installation instructions and then configure it to use the Paris PDO instance:
<?php
$container['db'] = $container->share(function(){
return ORM::get_db();
});
$container['phpmig.adapter'] = $container->share(function() use ($container) {
return new Adapter\PDO\Sql($container['db'], 'migrations');
});
Multiple Connections¶
Paris now works with multiple database conections (and necessarily relies on an updated version of Idiorm that also supports multiple connections). Database connections are identified by a string name, and default to OrmWrapper::DEFAULT_CONNECTION
(which is really ORM::DEFAULT_CONNECTION
).
See Idiorm’s documentation for information about configuring multiple connections.
The connection to use can be specified in two separate ways. To indicate a default connection key for a subclass of Model
, create a public static property in your model class called $_connection_name
.
<?php
// A named connection, where 'alternate' is an arbitray key name
ORM::configure('sqlite:./example2.db', null, 'alternate');
class SomeClass extends Model
{
public static $_connection_name = 'alternate';
}
The connection to use can also be specified as an optional additional parameter to OrmWrapper::for_table()
, or to Model::factory()
. This will override the default setting (if any) found in the $_connection_name
static property.
<?php
$person = Model::factory('Author', 'alternate')->find_one(1); // Uses connection named 'alternate'
The connection can be changed after a model is populated, should that be necessary:
<?php
$person = Model::factory('Author')->find_one(1); // Uses default connection
$person->orm = Model::factory('Author', 'alternate'); // Switches to connection named 'alternate'
$person->name = 'Foo';
$person->save(); // *Should* now save through the updated connection
Queries across multiple connections are not supported. However, as the Paris methods has_one
, has_many
and belongs_to
don’t require joins, these should work as expected, even when the objects on opposite sides of the relation belong to diffrent connections. The has_many_through
relationship requires joins, and so will not reliably work across different connections.