[Organization and sharing] 8 tips for using Laravel model timestamps

Below, the Laravel Tutorial column will share with you 8 tips on how to use Laravel model timestamps. See if you have never used them. If not, come and collect them. I hope it will be helpful to everyone!

By default, the Laravel Eloquent model default data tables include created_at and updated_at Two fields. Of course, we can make a lot of custom configurations and implement many interesting functions. Here are some examples.

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1. Disable timestamp

If the data table does not have these two fields, when saving the data Model::create($arrayOfValues); ——You will see SQL error. Laravel When automatically filling created_at / updated_at, these two fields cannot be found.

Disable automatic filling of timestamps, just add the previous attribute in Eloquent Model:

class Role extends Model
{
    public $timestamps = FALSE;

    // ... 其他的属性和方法
}

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2. Modify the default list of timestamps

What if you are currently using a non-Laravel type of database, that is, your timestamp column is named differently? Perhaps, they are called create_time and update_time respectively. Congratulations, you can also define it like this in the model:

class Role extends Model
{
    const CREATED_AT = 'create_time';
    const UPDATED_AT = 'update_time';

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3. Modify the timestamp date/time format

The following content refers to the official Laravel documentation :

By default, the timestamp is automatically formatted as 'Y-m-d H:i:s'. If you need to customize the timestamp format, you can set the $dateFormat property in your model. This property determines the format in which the date is stored in the database and when serialized into an array or JSON:

class Flight extends Model
{
    /**
     * 日期时间的存储格式
     *
     * @var string
     */
    protected $dateFormat = 'U';
}

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4. Many-to-many: Intermediate table with timestamp

When in a many-to-many association, the timestamp will not be automatically filled in, such as the intermediate table role_user# of the user table users and the role table roles ##.

In this model you can define the relationship like this:

class User extends Model
{
    public function roles()
    {
        return $this->belongsToMany(Role::class);
    }
}

Then when you want to add a role to the user, you can use it like this:

$roleID = 1;
$user->roles()->attach($roleID);

By default, this middle Table

does not contain timestamp . And Laravel will not try to automatically populate created_at/updated_at

but if you want to automatically save the timestamp, you need to add

created_at/updated_at in the migration file , and then add ->withTimestamps();

public function roles()
{
    return $this->belongsToMany(Role::class)->withTimestamps();
}

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5. Use latest() Andoldest()Perform timestamp sorting

There are two "shortcut methods" for using timestamp sorting.

Instead:

User::orderBy('created_at', 'desc')->get();

This is faster:

User::latest()->get();

By default,

latest() uses created_at sorting.

Correspondingly, there is an

oldest(), which will be sorted like this created_at ascending

User::oldest()->get();

Of course, you can also use other specified fields Sort. For example, if you want to use

updated_at, you can do this:

$lastUpdatedUser = User::latest('updated_at')->first();

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6. Do not trigger the modification of updated_at

Whenever an

Eloquent record is modified, the current timestamp will be automatically used to maintain the updated_at field, which is a great feature.

But sometimes you don’t want to do this. For example: when adding a certain value, you think this is not a “whole row update”.

Then you can do the same as above - just disable

timestamps and remember this is temporary:

$user = User::find(1);
$user->profile_views_count = 123;
$user->timestamps = false;
$user->save();

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7. Update times only Stamps and associated timestamps

Just the opposite of the previous example, maybe you need to update only the

updated_at field without changing the other columns.

So, the following writing method is not recommended:

$user->update(['updated_at' => now()]);

You can use a faster method:

$user->touch();

Another situation, sometimes you not only want to update the current model The

updated_at also hopes to update the record of the superior relationship.

For example, if a

comment is updated, then you want to update the updated_at of the post table.

Then, you need to define the

$touches attribute in the model:

class Comment extends Model {

    protected $touches = ['post'];

    public function post()
    {
        return $this->belongsTo('Post');
    }

}

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8. Timestamp field automatic conversionCarbonClass

One last tip, but more like a reminder since you should already know it.

By default, the

created_at and updated_at fields are automatically converted to $dates, so you don’t need to convert them to
Carbon instance, that is, the method of Carbon can be used.

For example:

$user->created_at->addDays(3);
now()->diffInDays($user->updated_at);

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That’s it, a quick but hopefully helpful tip!

English original address: https://laraveldaily.com/8-tricks-with-laravel-timestamps/

Translation address: https://learnku.com/laravel/ t/39353

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