A cheat sheet for Laravel’s Eloquent ORM version 5.5.
One to One Relationship
Demo details:
In this demo we have 2 models (Owner and Car), and 2 tables (owners and cars).
Business Rules:
The Owner can own one Car.The Car can be owned by one Owner.
Relations Diagram:
Relationship Details:
The Cars table should store the Owner ID.
Eloquent Models:
class Owner{public function car(){return $this->hasOne(Car::class);}}
class Car{public function owner(){return $this->belongsTo(Owner::class);}}
Database Migrations:
Schema::create('owners', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('cars', function (Blueprint $table) {$table->increments('id');$table->string('name');
$table->integer('owner\_id')->unsigned()->index()->nullable();
$table->foreign('owner\_id')->references('id')->on('owners');
});
Store Records:
// Create relation between Owner and Car.
$owner->car()->save($car);
// Create relation between Car and Owner.
$car->owner()->associate($owner)->save();
Retrieve Records:
// Get Owner Car
$owner->car;
// Get Car Owner
$car->owner;
One to Many Relationship
Demo details:
In this demo we have 2 models (Thief and Car), and 2 tables (thieves and cars).
Business Rules:
The Thief can steal many Cars.The Car can be stolen by one Thief.
Relations Diagram:
Relationship Details:
The Cars table should store the Thief ID.
Eloquent Models:
class Thief{public function cars(){return $this->hasMany(Car::class);}}
class Car{public function thief(){return $this->belongsTo(Thief::class);}}
Database Migrations:
Schema::create('thieves', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('cars', function (Blueprint $table) {$table->increments('id');$table->string('name');
$table->integer('thief\_id')->unsigned()->index()->nullable();
$table->foreign('thief\_id')->references('id')->on('thieves');
});
Store Records:
// Create relation between Thief and Car.
$thief->cars()->saveMany([$car1,$car2,]);
// Or use the save() function for single model.
$thief->cars()->save($car);
// Create relation between Car and Thief.
$car->thief()->associate($thief)->save();
Retrieve Records:
// Get Thief Car
$thief->cars;
// Get Car Thief
$car->thief;
Polymorphic One to Many Relationship
Demo details:
In this demo we have 3 models (Man, Woman and Car), and 3 tables (men, women and cars).
Business Rules:
The Man (buyer) can buy many Cars. The Woman (buyer) can buy many Cars.The Car can be bought by one buyer (Man or Woman).
Relations Diagram:
Relationship Details:
The Car table should store the Buyer ID and the Buyer Type. “buyer” is a name given to a group of models (Man and Woman). And it’s not limited to two. The buyer type is the real name of the model.
Eloquent Models:
class Man{public function cars(){return $this->morphMany(Car::class, 'buyer');}}
class Woman{public function cars(){return $this->morphMany(Car::class, 'buyer');}}
class Car{public function buyer(){return $this->morphTo();}}
Database Migrations:
Schema::create('men', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('women', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('cars', function (Blueprint $table) {$table->increments('id');$table->string('name');
$table->integer('buyer\_id')->unsigned()->index()->nullable();
$table->string('buyer\_type')->nullable();
// or use $table->morphs(‘buyer’); instead of "buyer\_id" and "buyer\_type"
});
Store Records:
// Create relation between buyer (Man/Woman) and Car.
$man->cars()->saveMany([$car1,$car2,]);
$woman->cars()->saveMany([$car1,$car2,]);
// Or use the save() function for single model.
$man->cars()->save($car);$woman->cars()->save($car);
// Create relation between Car and buyer (Men/Women).
$car1->buyer()->associate($man)->save();$car2->buyer()->associate($woman)->save();
Retrieve Records:
// Get buyer (Man/Woman) Cars
$men->cars$women->cars
// Get Car buyer (Man and Woman)
$car->buyer
Many to Many Relationship
Demo details:
In this demo we have 2 models (Driver and Car), and 3 tables (drivers, cars and a pivot table named car_driver).
Business Rules:
The Driver can drive many Cars.The Car can be driven by many Drivers.
Relations Diagram:
Relationship Details:
The Pivot table “car_driver” should store the Driver ID and the Car ID.
Eloquent Models:
class Driver{public function cars(){return $this->belongsToMany(Car::class);}}
class Car{public function drivers(){return $this->belongsToMany(Driver::class);}}
Database Migrations:
Schema::create('drivers', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('cars', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('car_driver', function (Blueprint $table) {$table->increments('id');
$table->integer('car\_id')->unsigned()->index();
$table->foreign('car\_id')->references('id')->on('cars')->onDelete('cascade');
$table->integer('driver\_id')->unsigned()->index();
$table->foreign('driver\_id')->references('id')->on('drivers')->onDelete('cascade');
});
Store Records:
// Create relation between Driver and Car.
$driver->cars()->attach([$car1->id,$car2->id,]);
// Or use the sync() function to prevent duplicated relations.
$driver->cars()->sync([$car1->id,$car2->id,]);
// Create relation between Car and Driver.
$car->drivers()->attach([$driver1->id,$driver2->id,]);
// Or use the sync() function to prevent duplicated relations.
$car->drivers()->sync([$driver1->id,$driver2->id,]);
Retrieve Records:
// Get Driver Car
$driver->cars
// Get Car Drivers
$car->drivers
Polymorphic Many to Many Relationship
Demo details:
In this demo we have 3 models (Valet, Owner and Car), and 4 tables (valets, owners, cars and drivers).
Business Rules:
The Valet (driver) can drive many Cars. The Owner (driver) can drive many Cars.The Car can be driven by many drivers (Valet or/and Owner).
Relations Diagram:
Relationship Details:
The Pivot table “drivers” should store the Driver ID, Driver Type and the Car ID.“driver” is a name given to a group of models (Valet and Owner). And it’s not limited to two. The driver type is the real name of the model.
Eloquent Models:
class Valet{public function cars(){return $this->morphToMany(Car::class, 'driver');}}
class Owner{public function cars(){return $this->morphToMany(Car::class, 'driver');}}
class Car{public function valets(){return $this->morphedByMany(Valet::class, 'driver');}
public function owners()
{
return $this->morphedByMany(Owner::class, 'driver');
}
}
Database Migrations:
Schema::create('valets', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('owners', function (Blueprint $table) {$table->increments('id');$table->string('name');});
Schema::create('drivers', function (Blueprint $table) {$table->increments('id');
$table->integer('driver\_id')->unsigned()->index();
$table->string('driver\_type');
// or use $table->morphs(‘driver’); instead of "driver\_id" and "driver\_type"
$table->integer('car\_id')->unsigned()->index();
$table->foreign('car\_id')->references('id')->on('cars')->onDelete('cascade');
});
Store Records:
// Create relation between driver (Valet/Owner) and Car.
$valet->cars()->saveMany([$car1, $car2]);$owner->cars()->saveMany([$car1, $car2]);
// Or use the save() function for single model.
$valet->cars()->save($car1);$owner->cars()->save($car1);
// Create relation between Car and driver (Valet/Owner).
$car->valets()->attach([$valet1->id,$valet2->id,]);
$car->owners()->attach([$owner1->id,$owner2->id,]);
// Or use the sync() function to prevent duplicated relations.
$car->valets()->sync([$valet1->id,$valet2->id,]);
$car->owners()->sync([$owner1->id,$owner2->id,]);
Retrieve Records:
// Get driver (Valet/Owner) Cars
$valet->cars$owner->cars
// Get Car drivers (Valet and Owner)
$car->owners$car->valets
Follow me on Twitter Mahmoud Zalt.
