This article mainly introduces the introduction of Laravel's Eloquent model. It has certain reference value. Now I share it with everyone. Friends in need can refer to it.
Default Inherit the use Illuminate\Database\Eloquent\Model class.
#Data table name and model name convention:
The database table names are generally named using the "snake nomenclature". Snake nomenclature requires words to be lowercase, words to be connected by _underscores, and names to be plural.
##The corresponding model name is named using the "Pascal method" , that is, the first letter of each word is capitalized.
If the above agreement is not followed, the corresponding data table needs to be specified: class Flight extends Model
{ /**
* 与模型关联的数据表
*
* @var string */
protected $table = 'myflights';
}
class Flight extends Model
{ /**
* 与模型关联的数据表 */
protected $table = 'my_flights'; protected $primaryKey='mid'; //自定义主键字段
protected $keyType = 'string'; //自定义主键类型为字串
public $incrementing = false; //主键非自增型}The model has two fields, created_at and updated_at by default. You can set $timestamps without the two fields:
class Flight extends Model
{ /**
* 该模型是否被自动维护时间戳 */
public $timestamps = false;
}$dateFormat attribute can customize the time cutoff format stored in the data table:
class Flight extends Model
{ /**
* 模型的日期字段的存储格式 */
protected $dateFormat = 'U';
}Customized time cutoff field name:
<?phpclass Flight extends Model
{ const CREATED_AT = 'creation_date'; const UPDATED_AT = 'last_update';
}class Flight extends Model
{ /**
* 此模型的连接名称。 */
protected $connection = 'connection-name';
}
use App\Flight;$flights = App\Flight::all(); //查询所有数据
foreach ($flights as $flight) { echo $flight->name;
}$flights = App\Flight::where('active', 1)
->orderBy('name', 'desc')
->take(10)
->get(); //有条件地查询数据
instances. If you query large batches of data, you can use chunks to save memory:
Flight::chunk(200, function ($flights) { foreach ($flights as $flight) { // }
});Or use the cursor method cursor to greatly reduce memory usage:
foreach (Flight::where('foo', 'bar')->cursor() as $flight) { //}// 通过主键取回一个模型...$flight = App\Flight::find(1);
// 取回符合查询限制的第一个模型 ...
$flight = App\Flight::where('active', 1)->first();//如果找不到模型则抛出异常
//Illuminate\Database\Eloquent\ModelNotFoundException
//自动返回 HTTP 404 响应给用户
$model = App\Flight::where('legs', '>', 100)->firstOrFail();
$count = App\Flight::where('active', 1)->count();$max = App\Flight::where('active', 1)->max('price');
save method: Need to retrieve once first, and then set to update Then execute the save method for the attribute, and updated_at will be automatically updated at the same time.
Update method: Set the where condition and pass the update field into the update method as a key-value pair. The update does not trigger saved and updated model events.
$flight = App\Flight::find(1); $flight->name = 'New Flight Name';$flight->save(); //查询一次后再更新 App\Flight::where('active', 1) ->where('destination', 'San Diego') ->update(['delayed' => 1]); //设置条件后再批量更新
To use the model to create data, you need to set the $fillable or $guarded attribute first. You can only choose one of the two attributes.
class Flight extends Model
{ /**
* 可以被批量赋值的属性。
* @var array */
protected $fillable = ['name'];
}class Flight extends Model
{ /**
* 不可被批量赋值的属性。可定义为空数组，表示所有属性都可以赋值。
* @var array */
protected $guarded = ['price'];
}Method of inserting data:
$flight = App\Flight::create(['name' => 'Flight 10']); //添加新记录并返回已保存的模型实例 $flight->fill(['name' => 'Flight 22']); //已有实例模型可使用fill方法
// 通过 name 属性检索航班，当结果不存在时创建它...
$flight = App\Flight::firstOrCreate(['name' => 'Flight 10']);// 通过 name 属性检索航班，当结果不存在的时候用 name 属性和 delayed 属性去创建它$flight = App\Flight::firstOrCreate(
['name' => 'Flight 10'], ['delayed' => 1]
);// 通过 name 属性检索航班，当结果不存在时实例化...
$flight = App\Flight::firstOrNew(['name' => 'Flight 10']);// 通过 name 属性检索航班，当结果不存在的时候用 name 属性和 delayed 属性实例化$flight = App\Flight::firstOrNew(
['name' => 'Flight 10'], ['delayed' => 1]
);// 如果有从奥克兰飞往圣地亚哥的航班，将价格设为 99 美元
// 如果不存在匹配的模型就创建一个
$flight = App\Flight::updateOrCreate(
['departure' => 'Oakland', 'destination' => 'San Diego'],
['price' => 99]
);firstOrCreate: If the data cannot be found, create a record based on the first parameter and second parameter record and return the saved model;
firstOrNew: If the data cannot be found, a new model will be created based on the first and second parameter records, but the data will not be saved. You need to save it manually to save the data;
updateOrCreate: Based on the first parameter Use the condition to update the second parameter data. If the data does not exist, merge the two parameters to create a record and return the saved model.
Delete models:
$flight = App\Flight::find(1);$flight->delete(); //通过查询所得的模型实例进行delete方法删除 //通过主键删除一至多条数据：App\Flight::destroy(1); App\Flight::destroy([1, 2, 3]); App\Flight::destroy(1, 2, 3);//通过查询条件批量删除，并返回删除条数 $deletedRows = App\Flight::where('active', 0)->delete();
When deleting in batches, the deleted and deleting model events will not be triggered.
Soft deletion:
The data table should set the deleted_at field. Reference the SoftDeletes trait in the model and set the deleted_at field to the $dates attribute.
<?php
namespace App;use Illuminate\Database\Eloquent\Model;use Illuminate\Database\Eloquent\SoftDeletes;class Flight extends Model
{ use SoftDeletes; /**
* 需要被转换成日期的属性。
* @var array */
protected $dates = ['deleted_at'];
}The soft deletion model is set, and deleted_at is set to the current date and time in the delete method. Querying soft-deleted models will automatically exclude soft-deleted models.
if ($flight->trashed()) { //检查该模型实例是否被软删除}$flights = App\Flight::withTrashed() //能使用查询包含软删除的数据
->where('account_id', 1) ->get();$flights = App\Flight::onlyTrashed() //只查询软删除的数据
->where('airline_id', 1) ->get();$flight->restore(); //恢复被软删除的模型App\Flight::withTrashed() //批量恢复模型，不会触发任何模型事件
->where('airline_id', 1) ->restore();Soft delete model uses force delete:
$flight->forceDelete();##Query scope:
Add query constraints to the model. There are two types: global and local: global--conditional constraints are automatically added to each query; local--local constraints are called as needed. Global scope: First you need to implement the scope interface class.<?php
namespace App\Scopes;use Illuminate\Database\Eloquent\Scope;use Illuminate\Database\Eloquent\Model;use Illuminate\Database\Eloquent\Builder;class AgeScope implements Scope
{ /**
* 将范围应用于给定的 Eloquent 查询生成器
*
* @param \Illuminate\Database\Eloquent\Builder $builder
* @param \Illuminate\Database\Eloquent\Model $model
* @return void */
public function apply(Builder $builder, Model $model)
{ return $builder->where('age', '>', 200);
}
}addSelect
method instead ofselect to avoid replacing the query's existing select. Apply global scope:
<?php
namespace App;use App\Scopes\AgeScope;use Illuminate\Database\Eloquent\Model;class User extends Model
{ /**
* 模型的「启动」方法
*
* @return void */
protected static function boot()
{
parent::boot(); static::addGlobalScope(new AgeScope);
}
}class User extends Model
{ /**
* 模型的「启动」方法
*
* @return void */
protected static function boot()
{
parent::boot();
static::addGlobalScope('age', function(Builder $builder) {
$builder->where('age', '>', 200);
});
}
}User::withoutGlobalScope(AgeScope::class)->get(); //删除指定的作用域
// 删除所有的全局作用域User::withoutGlobalScopes()->get();// 删除一些全局作用域User::withoutGlobalScopes([
FirstScope::class, SecondScope::class])->get();定义通用的约束在需要时使用。定义方法：在模型内定义scope前缀的方法。
<?php
namespace App;use Illuminate\Database\Eloquent\Model;class User extends Model
{ /**
* 限制查询只包括受欢迎的用户。
*
* @return \Illuminate\Database\Eloquent\Builder */
public function scopePopular($query)
{ return $query->where('votes', '>', 100);
} /**
* 限制查询只包括活跃的用户。
*
* @return \Illuminate\Database\Eloquent\Builder */
public function scopeActive($query)
{ return $query->where('active', 1);
}
}使用方法：
$users = App\User::popular()->active()->orderBy('created_at')->get();
动态作用域：
class User extends Model
{ /**
* 限制查询只包括指定类型的用户。
*
* @return \Illuminate\Database\Eloquent\Builder */
public function scopeOfType($query, $type)
{ return $query->where('type', $type);
}
}//调用作用域时传参$users = App\User::ofType('admin')->get();模型事件：
retrieved --查询触发
creating、created--创建触发
updating、updated--更新触发
saving、saved--创建、更新触发
deleting、deleted--删除触发
restoring、restored--恢复触发
事件指派相应的监控器：
<?php
namespace App;use App\Events\UserSaved;use App\Events\UserDeleted;
use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;class User extends Authenticatable
{ use Notifiable; /**
* 模型的事件映射。
*
* @var array */
protected $dispatchesEvents = [ 'saved' => UserSaved::class, //触发saved事件，调用UserSaved监控器
'deleted' => UserDeleted::class, //触发deleted事件，调用UserDeleted监控器 ];
}也可所有监听放在一个观察器类中：
<?php
namespace App\Observers;use App\User;class UserObserver
{ /**
* 监听用户创建的事件。
*
* @param User $user
* @return void */
public function created(User $user)
{ // } /**
* 监听用户删除事件。
*
* @param User $user
* @return void */
public function deleting(User $user)
{ // }
}注册观察器：
<?php
namespace App\Providers;use App\User;use App\Observers\UserObserver;
use Illuminate\Support\ServiceProvider;class AppServiceProvider extends ServiceProvider
{ /**
* 运行所有应用.
*
* @return void */
public function boot()
{
User::observe(UserObserver::class);
}
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