I’m trying to give simple examples of the two types of lines. In the first diagram, the solid line shows an association: If the classes were declared in Java, this would be like ClassA storing a reference to ClassB as an attribute (it could be passed in to the constructor, created, etc.). So, you might … Read more
Something like this should work foo.findAll({ where : where, attributes : attributes, include : [{ model: bar, attributes: attributes}] }).success(function (result) {
attach(): Insert related models when working with many-to-many relations No array parameter is expected Example: $user = User::find(1); $user->roles()->attach(1); sync(): Similar to the attach() method, the sync() method is used to attach related models. However, the main differences are: sync() accepts an array of IDs to place on the pivot table Secondly, most important, the … Read more
As of 2.3.0 and up to 3.3.0 MATCH (n) DETACH DELETE n Docs Pre 2.3.0 MATCH (n) OPTIONAL MATCH (n)-[r]-() DELETE n,r Docs
tldr; Use sync with 2nd param false Many-to-many relationship is belongsToMany on both models: // Task model public function users() { return $this->belongsToMany(‘User’, ‘user_tasks’); // assuming user_id and task_id as fk } // User model public function tasks() { return $this->belongsToMany(‘Task’, ‘user_tasks’); } In order to add new relation use attach or sync. Difference between … Read more
Composition final class Car { private final Engine engine; Car(EngineSpecs specs) { engine = new Engine(specs); } void move() { engine.work(); } } Aggregation final class Car { private Engine engine; void setEngine(Engine engine) { this.engine = engine; } void move() { if (engine != null) engine.work(); } } In the case of composition, the … Read more
The correct syntax to do this on your relations is: Event::whereHas(‘participants’, function ($query) { return $query->where(‘IDUser’, ‘=’, 1); })->get(); This will return Events where Participants have a user ID of 1. If the Participant doesn’t have a user ID of 1, the Event will NOT be returned. Read more at https://laravel.com/docs/5.8/eloquent-relationships#eager-loading
It is possible to extend the relation with query functions: <?php public function comments() { return $this->hasMany(‘Comment’)->orderBy(‘column’); } [edit after comment] <?php class User { public function comments() { return $this->hasMany(‘Comment’); } } class Controller { public function index() { $column = Input::get(‘orderBy’, ‘defaultColumn’); $comments = User::find(1)->comments()->orderBy($column)->get(); // use $comments in the template } } … Read more
With with() is for eager loading. That basically means, along the main model, Laravel will preload the relationship(s) you specify. This is especially helpful if you have a collection of models and you want to load a relation for all of them. Because with eager loading you run only one additional DB query instead of … Read more
One-to-one: Use a foreign key to the referenced table: student: student_id, first_name, last_name, address_id address: address_id, address, city, zipcode, student_id # you can have a # “link back” if you need You must also put a unique constraint on the foreign key column (addess.student_id) to prevent multiple rows in the child table (address) from relating … Read more