本篇文章给大家带来了关于laravel的相关知识，其中主要跟大家介绍laravel eloquent模型中乐观锁的实现，有代码示例，感兴趣的朋友下面一起来看一下吧，希望对大家有帮助。
在app/Utils/Traits目录下创建OptimisticLockTrait.php，代码如下：
namespace App\Utils\Traits;use Illuminate\Database\Eloquent\Builder;trait OptimisticLockTrait{ /** * @var array $optimisticConditions * @var array $bindings */ protected $optimisticConditions, $bindings; /** * @var string $optimisticConditionRaw */ protected $optimisticConditionRaw; /** * save 时增加乐观锁条件 * @param Builder $builder */ protected function performUpdate(Builder $builder) { if (!empty($this->optimisticConditions)) { foreach ($this->optimisticConditions as $field => $value) { if (is_array($value)) { $count = count($value); if ($count >= 3) { switch (strtoupper($value[1])) { case 'IN': $builder->whereIn($value[0], $value[2]); break; case 'NOT IN': $builder->whereNotIn($value[0], $value[2]); break; case 'BETWEEN': $builder->whereBetween($value[0], $value[2]); break; case 'NOT BETWEEN': $builder->whereNotBetween($value[0], $value[2]); break; default: $builder->where($value[0], $value[1], $value[2]); } } else { $builder->where($value); } } else { $builder->where($field, $value); } } } // 原始条件注入 if ($this->optimisticConditionRaw) $builder->whereRaw($this->optimisticConditionRaw, $this->bindings); return $this->clearOptimistic()->perFormUpdating($builder); } /** * updating with optimistic * * @param Builder $builder * @return bool */ protected function perFormUpdating(Builder $builder) { // If the updating event returns false, we will cancel the update operation so // developers can hook Validation systems into their models and cancel this // operation if the model does not pass validation. Otherwise, we update. if ($this->fireModelEvent('updating') === false) { return false; } // First we need to create a fresh query instance and touch the creation and // update timestamp on the model which are maintained by us for developer // convenience. Then we will just continue saving the model instances. if ($this->usesTimestamps()) { $this->updateTimestamps(); } // Once we have run the update operation, we will fire the "updated" event for // this model instance. This will allow developers to hook into these after // models are updated, giving them a chance to do any special processing. $dirty = $this->getDirty(); $res = 0; if (count($dirty) > 0) { $res = $this->setKeysForSaveQuery($builder)->update($dirty); $this->syncChanges(); $this->fireModelEvent('updated', false); } return !empty($res); } // 清除乐观锁条件 function clearOptimistic() { $this->optimisticConditions = null; $this->optimisticConditionRaw = null; return $this; } // 设置乐观锁条件字段名列表 function setOptimistic(array $optimisticConditions) { $this->optimisticConditions = $optimisticConditions; return $this; } // 设置乐观锁原始条件字段名列表 function setOptimisticRaw(string $optimisticConditionRaw, array $bindings = []) { $this->optimisticConditionRaw = $optimisticConditionRaw; $this->bindings = $bindings; return $this; }}
乐观锁使用说明
1、在模型中(Models)或模型父类使用
/*** App\Models\BaseModel* @mixin \Eloquent* @method static \Illuminate\Database\Eloquent\Builder|BaseModel newModelQuery()* @method static \Illuminate\Database\Eloquent\Builder|BaseModel newQuery()* @method static \Illuminate\Database\Eloquent\Builder|BaseModel query()*/class BaseModel extends Model{ use OptimisticLockTrait;}
2、使用方法：
$ord = Order::find(1); $ord->payment_status = 1; if(!$model->setOptimistic(['payment_status' => 0]))->save()) throws new Exception('订单已付过款了');
或者使用原始SQL方式:
$ord = Order::find(1); $ord->payment_status = 1; if(!$model->setOptimisticRaw('payment_status = ?',[1]))->save()) throws new Exception('订单已付过款了');
如果同一对象小涉及到多次更新，则可以清除锁条件
$ord->clearOptimistic();
以上就是乐观锁的实现方式，在实际开发中比较常用也很有必要。
推荐学习：《laravel视频教程》
以上就是Laravel Eloquent模型中乐观锁的实现的详细内容，更多请关注创想鸟其它相关文章！
版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。
如发现本站有涉嫌抄袭侵权/违法违规的内容， 请发送邮件至 chuangxiangniao@163.com 举报，一经查实，本站将立刻删除。
发布者：程序猿，转转请注明出处：https://www.chuangxiangniao.com/p/40332.html
微信扫一扫 
支付宝扫一扫 
