在laravel模型中的scope范围查询之查询作用域

本文简单了解一下laravel Scope的全局范围、本地范围、动态作用域等使用示例代码

全局范围

让我们在app/Scopes/HasActiveScope.php文件中创建一个新的类, 内容如下

<?php
namespace App\Scopes;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Scope;
class HasActiveScope implements Scope
{
    /**
     * Apply the scope to a given Eloquent query builder.
     *
     * @param  \Illuminate\Database\Eloquent\Builder  $builder
     * @param  \Illuminate\Database\Eloquent\Model  $model
     * @return void
     */
    public function apply(Builder $builder, Model $model)
    {
        $builder->where('active', true);
    }
}

你应该覆盖模型的booted方法并调用模型的addGlobalScope方法。

addGlobalScope 方法接受你的作用域的一个实例作为它的唯一参数

<?php
namespace App\Models;
use App\Scopes\HasActiveScope;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
    /**
     * The "booted" method of the model.
     *
     * @return void
     */
    protected static function booted()
    {
        // using seperate scope class
        static::addGlobalScope(new HasActiveScope);
        // you can do the same thing using anonymous function
        // let's add another scope using anonymous function
        static::addGlobalScope('delete', function (Builder $builder) {
            $builder->where('deleted', false);
        });
    }

使用全局范围

# fetching all active and non-deleted users
$users = User::all();
# above query will result in following sql
select * from `users` where `active` = 1 and `deleted` = 0

从查询中删除范围

你可能不希望你的全局过滤器被应用。例如，如果你想获取所有的用户，无论他们是否处于活动状态。

在这种情况下，你可以用下面的例子删除你应用的范围

# fetch all users weather they are active or not
$users = User::withoutGlobalScope(new HasActiveScope)->all();
# fetch active users weather they are deleted or not
User::withoutGlobalScope('delete')->all();

本地范围

本地作用域是以Scope关键字为前缀的。在这种情况下，你可以在你的Laravel模型中添加本地作用域，而不是定义全局作用域，如下所示

<?php
namespace App\Models;
use App\Scopes\HasActiveScope;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
    public function scopeActive($query)
    {
        return $query->where('active', 1);
    }
    public function scopeDelete($query)
    {
        return $query->where('delete', 0);
    }
}

使用本地范围

# apply active local scope to following query
$users = User::active()->orderBy('created_at')->get();
# apply delete local scope to following query
$users = User::delete()->orderBy('created_at')->get();

动态作用域

有时你可能想给你的局部作用域传递额外的参数。在这种情况下，我们可以向我们的局部作用域传递动态参数，它将作为动态作用域。

<?php
namespace App\Models;
use App\Scopes\HasActiveScope;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
    public function scopeActive($query)
    {
        return $query->where('active', 1);
    }
    public function scopeDelete($query)
    {
        return $query->where('delete', 0);
    }
    public function scopeWithRole($query, $role)
    {
        return $query->where('role', $role);
    }
}

使用动态作用域

# find active users with role admin
$users = User::active()->withRole('admin')->all();

我希望对你有所帮助！