Eloquent és un ORM (Object Relational Mapping), és a dir, una llibreria/eina que facilita la creació d'objectes de programació a partir de la informació d'una font de persistència (p.ex. un base de dades). Eloquent és part de Laravel i proporciona una implementació del patró ActiveRecord per tal de treballar amb la base de dades de l'aplicació. Cada taula de la base de dades té el seu corresponent Model (una classe que hereta de la classe Model) i que és la classe utilitzada per interactuar amb la taula.
Vegeu com configurar l'accés a base de dades (fitxer config/database.php) a l'article Laravel Database i també com funcionen les migracions Laravel per a la creació de l'estructura de la base de dades així com les comandes que ofereix artisan per a facilitar la creació de migracions (php artisan migrate) i la creació de models (php artisan Model:create)
TODO
http://laravel.com/docs/5.2/eloquent#relationships
Tipus de relacions:
Un altre exemple: http://ryantablada.com/post/pivot-tables-vs-pivot-models Vegeu també pivot table o Associative entity
For people struggling with it, the approach I took was simply to create an intermediary model and access it that way. Instead of thinking of it like user, user_group, and group, I thought of it like user, membership, group.
Acacha Wiki//user.php
public function memberships(){
return $this->hasMany('Membership');
}
if you feel safe enough you can do the belongs to many with group directly as well for easy access but it's a bit dangerous when things start to get complex
//membership.php
public function user(){
return $this->belongsTo('User');
}
public function group(){
return $this->belongsTo('Group');
}
//group.php
public function memberships(){
return $this->hasMany('Membership');
}
Recursos:
Example: Bears, Fish, Trees and Picnics from [1]:
<?php
class Bear extends Eloquent {
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
// we only want these 3 attributes able to be filled
protected $fillable = array('name', 'type', 'danger_level');
// DEFINE RELATIONSHIPS --------------------------------------------------
// each bear HAS one fish to eat - ONE TO ONE
public function fish() {
return $this->hasOne('Fish'); // this matches the Eloquent model
}
// each bear climbs many trees. ONE TO MANY
public function trees() {
return $this->hasMany('Tree');
}
// each bear BELONGS to many picnic
// define our pivot table also --> MANY TO MANY
public function picnics() {
return $this->belongsToMany('Picnic', 'bears_picnics', 'bear_id', 'picnic_id');
}
}
// app/models/Fish.php
<?php
class Fish extends Eloquent {
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
// we only want these 3 attributes able to be filled
protected $fillable = array('weight', 'bear_id');
// LINK THIS MODEL TO OUR DATABASE TABLE ---------------------------------
// since the plural of fish isnt what we named our database table we have to define it
protected $table = 'fish';
// DEFINE RELATIONSHIPS --------------------------------------------------
public function bear() {
return $this->belongsTo('Bear');
}
}
// app/models/Tree.php
<?php
class Tree extends Eloquent {
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
// we only want these 3 attributes able to be filled
protected $fillable = array('type', 'age', 'bear_id');
// DEFINE RELATIONSHIPS --------------------------------------------------
public function bear() {
return $this->belongsTo('Bear');
}
}
// app/models/Picnic.php
<?php
class Picnic extends Eloquent {
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
// we only want these 3 attributes able to be filled
protected $fillable = array('name', 'taste_level');
// DEFINE RELATIONSHIPS --------------------------------------------------
// define a many to many relationship
// also call the linking table
public function bears() {
return $this->belongsToMany('Bear', 'bears_picnics', 'picnic_id', 'bear_id');
}
}
Migracions:
Schema::create('bears', function(Blueprint $table)
{
$table->increments('id');
$table->string('name');
$table->string('type');
$table->integer('danger_level'); // this will be between 1-10
$table->timestamps();
});
Schema::create('fish', function(Blueprint $table)
{
$table->increments('id');
$table->integer('weight'); // we'll use this to demonstrate searching by weight
$table->integer('bear_id'); // this will contain our foreign key to the bears table
$table->timestamps();
});
Schema::create('trees', function(Blueprint $table)
{
$table->increments('id');
$table->string('type');
$table->integer('age'); // how old is the tree
$table->integer('bear_id'); // which bear climbs this tree
$table->timestamps();
});
Schema::create('picnics', function(Blueprint $table)
{
$table->increments('id');
$table->string('name');
$table->integer('taste_level'); // how tasty is this picnic?
$table->timestamps();
});
Schema::create('bears_picnics', function(Blueprint $table)
{
$table->increments('id');
$table->integer('bear_id'); // the id of the bear
$table->integer('picnic_id'); // the id of the picnic that this bear is at
$table->timestamps();
});
Resources:
Vegeu també CRUD. Codi font:
https://github.com/scotch-io/laravel-eloquent-guide
Resources:
S'utilitza de la mateixa forma que amb els Laravel Database Seeders:
// create a bear
Bear::create(array(
'name' => 'Super Cool',
'type' => 'Black',
'danger_level' => 1
));
// alternatively you can create an object, assign values, then save
$bear = new Bear;
$bear->name = 'Super Cool';
$bear->type = 'Black';
$bear->danger_level = 1;
// save the bear to the database
$bear->save();
Una opció alternativa:
$bear = new Bear(); $bear->name = "Paquito"; $bear->type = "Negre"; $bear->danger_level = "7"; $bear->save();
Opcions alternatives són:
Exemples:
// find the bear or create it into the database
Bear::firstOrCreate(array('name' => 'Lawly'));
// find the bear or instantiate a new instance into the object we want
$bear = Bear::firstOrNew(array('name' => 'Cerms'));
Exemples:
// get all the bears
$bears = Bear::all();
// find a specific bear by id
$bear = Bear::find(1);
// find a bear by a specific attribute
$bearLawly = Bear::where('name', '=', 'Lawly')->first();
// find a bear with danger level greater than 5
$dangerousBears = Bear::where('danger_level', '>', 5)->get();
First vs Get
Al buscar registres a la base de dades amb get es poden obtenir un o més registres i amb first sempre està limitat a 1 registra (en cas de trobar múltiples s'utilitza el primer)
Exemples:
// let's change the danger level of Lawly to level 10
// find the bear
$lawly = Bear::where('name', '=', 'Lawly')->first();
// change the attribute
$lawly->danger_level = 10;
// save to our database
$lawly->save();
Exemples:
// find and delete a record
$bear = Bear::find(1);
$bear->delete();
// delete a record
Bear::destroy(1);
// delete multiple records
Bear::destroy(1, 2, 3);
// find and delete all bears with a danger level over 5
Bear::where('danger_level', '>', 5)->delete();
Vegeu Laravel Seeds
Eloquent
Model::create(array('key' => 'value'));
// Find first matching record by attributes or create
Model::firstOrCreate(array('key' => 'value'));
// Find first record by attributes or instantiate
Model::firstOrNew(array('key' => 'value'));
// Create or update a record matching attibutes, and fill with values
Model::updateOrCreate(array('search_key' => 'search_value'), array('key' => 'value'));
// Fill a model with an array of attributes, beware of mass assignment!
Model::fill($attributes);
Model::destroy(1);
Model::all();
Model::find(1);
// Find using dual primary key
Model::find(array('first', 'last'));
// Throw an exception if the lookup fails
Model::findOrFail(1);
// Find using dual primary key and throw exception if the lookup fails
Model::findOrFail(array('first', 'last'));
Model::where('foo', '=', 'bar')->get();
Model::where('foo', '=', 'bar')->first();
// dynamic
Model::whereFoo('bar')->first();
// Throw an exception if the lookup fails
Model::where('foo', '=', 'bar')->firstOrFail();
Model::where('foo', '=', 'bar')->count();
Model::where('foo', '=', 'bar')->delete();
//Output raw query
Model::where('foo', '=', 'bar')->toSql();
Model::whereRaw('foo = bar and cars = 2', array(20))->get();
Model::remember(5)->get();
Model::remember(5, 'cache-key-name')->get();
Model::cacheTags('my-tag')->remember(5)->get();
Model::cacheTags(array('my-first-key','my-second-key'))->remember(5)->get();
Model::on('connection-name')->find(1);
Model::with('relation')->get();
Model::all()->take(10);
Model::all()->skip(10);
// Default Eloquent sort is ascendant
Model::all()->orderBy('column');
Model::all()->orderBy('column','desc');
Soft Delete
Model::withTrashed()->where('cars', 2)->get();
// Include the soft deleted models in the results
Model::withTrashed()->where('cars', 2)->restore();
Model::where('cars', 2)->forceDelete();
// Force the result set to only included soft deletes
Model::onlyTrashed()->where('cars', 2)->get();
Events
Model::creating(function($model){});
Model::created(function($model){});
Model::updating(function($model){});
Model::updated(function($model){});
Model::saving(function($model){});
Model::saved(function($model){});
Model::deleting(function($model){});
Model::deleted(function($model){});
Model::observe(new FooObserver);
Eloquent Configuration
// Disables mass assignment exceptions from being thrown from model inserts and updates
Eloquent::unguard();
// Renables any ability to throw mass assignment exceptions
Eloquent::reguard();