Forem: Rafael França

Cascading on update (and on delete) in migration

Rafael França — Sun, 26 Jul 2020 00:19:04 +0000

That Laravel’s documentation is rich in content no one can deny, but it does not mean that it has everything it can offer us.

An example is when we need to perform a cascading update, some indicate the use of static methods in the model. But, there is a simpler way that few developers know, and is not explicit in the documentation.

On update

An example how our code would look like:



Schema::create('posts', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('author')->unsigned();
    $table->timestamps();
    $table->foreign('author')->references('id')->on('users')->onUpdate('cascade');
});

Now, our cascading on update it’s in the migration.

On delete

If I want to cascade on delete?



Schema::create('posts', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('author')->unsigned();
    $table->timestamps();
    $table->foreign('author')->references('id')->on('users')->onDelete('cascade');
});

It's easy, right? Let's avance.

Combine On update and On delete

If, I want to use on update and on delete in the same column? Yes, you can!



Schema::create('posts', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('author')->unsigned();
    $table->timestamps();
    $table->foreign('author')->references('id')->on('users')->onDelete('cascade')->onUpdate('cascade');
});

Changes on Laravel 7

In your 7th version, Laravel bring us some new use case:



Schema::create('posts', function (Blueprint $table) {
    $table->id();
    $table->foreignId('author')->constrained('users')->onDelete('cascade')->onUpdate('cascade');
    $table->timestamps();
});

Let me explain the changes:

id() it's the same of bigIncrements('id'). If you want to change the column name from id to cid, for eg., you can use id('cid');
foreignId('author') it's the same of unsignedBigInteger('author');
constrained('users') it's the same of references('id')->on('users'), that by default references the id

Advanced

By default, constrained() references the id, but you can change this, passing a second param, for eg., constrained('users', 'cid'), in this case, it's the same of references('cid')->on('users').

More advanced

By default, constrained() not need the first param, if you use the default structure of database (tables name in plural and in english), and your foreignId() is like this foreignId('user_id'), you can use only $table->foreignId('author')->constrained().

From behind, Laravel get the your foreignId that's user_id, and select all before the last undeline, in our eg, user, and apply the plural, that convert in users, it's the name of table. And, all after last underline will be the name of the column.

In the end, foreignId('user_id')->constrained(), it's the same of foreign('user_id')->references('id')->on('users'), even as foreignId('user_cid')->constrained(), it's the same of foreign('user_cid')->references('cid')->on('users').

What do you think about this tip?

Soon I back with more! :)

PS: Originally posted on my account on Medium.

Laravel Tip — Cascading on update in migration | by Rafael França | Medium

Rafael França ・ May 22, 2018 ・
Medium

Attribute Casting with Laravel

Rafael França — Sat, 25 Jul 2020 21:40:41 +0000

When was developing an application that use the MVC pattern, we need define our model, that is the layer that communicate our application with the database.

But sometimes, we need to casting values that received from model. Let me show an example:

You’re creating a model to represent Products, and need of: name, value, state (if it’s available or not) and when will it be available.

Every time that you need create, show or edit a product, need to casting the values. Our idea with this article is it makes your job easier, therefore, what about if we pass this responsibility to our model, so that it makes this automatically?

For this, Laravel has the $casts property. Let’s see how works:

Using this property, the attributes are casted automatically, and you not will need make this manually. Let’s see a practical example.

You’re create a method to add some days of delay in the availability of a product, for this, hasn’t used a date, only the quantities of days that want to delay.

Without use the $casts, you make something like this:

Note that we used the Carbon package to make a parse of the date and after add the quantities of days that want to be delayed.

And, if we use $casts, how would it be? Let’s see:

More simple and cleaner, sure?

You can think: “OK, I make this but, what I win, beyond save letters that will be typed?”.

The response to this question is: maintainability. That is, if in the future, you want to know the date and time that a product will be available, only need change your model, changing your $casts from date to datetime. It’s simple

What do you think about this tip?

Soon I back with more! :)

PS: Originally posted on my account on Medium.

Attribute Casting with Laravel. When was developing an application that… | by Rafael França | Medium

Rafael França ・ May 31, 2020 ・
Medium

Cover photo by Fotis Fotopoulos on Unsplash.

Dynamic queries with Laravel

Rafael França — Sat, 25 Jul 2020 21:25:32 +0000

When developing a project for a client, a doubt arose: how create a dynamic query using only Eloquent?

Maybe, you can think: “It’s easy! We can use the method when”.
But that wasn’t what I intended, therefore, before continue, let me show you better the problem.

Imagine that I have a schedule, and I need create an event that start and finish with a difference of weeks and has a repetition in specific days of week. E.g.:

I, Rafael, intent elevate my English and Spanish level, therefore, intent study English by one hour, in every Sunday, Wednesday and Friday, during a one month; and, Spanish, every Tuesday, Thursday and Saturday.

Now, imagine that you receive the dates using a numeric representation, in that 0 is equals a Monday, and 6 is a Saturday, thus we can represent the received data by the vector below:

{
    "frequency": "daily",
    "days": [1, 3, 5],
    "date_start": "29/05/2020",
    "date_end": "29/06/2020",
    "hour_start": "20:00",
    "hour_end": "21:00"
}

As every people that want to study, not like be interrupted to make another thing, therefore, we need grant this event not collide with another. So, more one time, how make this, using only Eloquent?

The response is simple. See above:

[...]

})->when(request()->get('frequency') === "daily", function (Builder $subquery) {
    foreach (request()->get('days') as $day) {
        $subquery->where('days', 'LIKE', "%$day%");
    }
    return $subquery;
});

[...]

What do you think about the tip?

Soon I back with more! :)

PS: Originally posted on my account on Medium.

Dynamic queries with Laravel. When developing a project for a client… | by Rafael França | Medium

Rafael França ・ May 30, 2020 ・
Medium

Cover photo by Chris Ried on Unsplash.

Forem: Rafael França

Cascading on update (and on delete) in migration

On update

On delete

Combine On update and On delete

Changes on Laravel 7

Advanced

More advanced

Laravel Tip — Cascading on update in migration | by Rafael França | Medium

Rafael França ・ May 22, 2018 ・ Medium

Attribute Casting with Laravel

Attribute Casting with Laravel. When was developing an application that… | by Rafael França | Medium

Rafael França ・ May 31, 2020 ・ Medium

Dynamic queries with Laravel

Dynamic queries with Laravel. When developing a project for a client… | by Rafael França | Medium

Rafael França ・ May 30, 2020 ・ Medium

Rafael França ・ May 22, 2018 ・
Medium

Rafael França ・ May 31, 2020 ・
Medium

Rafael França ・ May 30, 2020 ・
Medium