This article brings you relevant knowledge about Laravel. It mainly introduces to you the implementation of optimistic locking in the Laravel Eloquent model. There are code examples. Friends who are interested can take a look below. I hope it will be useful to you. help.

Create OptimisticLockTrait.php in the app/Utils/Traits directory, the code is as follows:

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?時增加樂觀鎖條件
?????*?@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);
????????????????}
????????????}
????????}
????????//?原始條件注入
????????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);
????}

????//?清除樂觀鎖條件
????function?clearOptimistic()
????{
????????$this->optimisticConditions?=?null;
????????$this->optimisticConditionRaw?=?null;
????????return?$this;
????}


????//?設(shè)置樂觀鎖條件字段名列表
????function?setOptimistic(array?$optimisticConditions)
????{
????????$this->optimisticConditions?=?$optimisticConditions;
????????return?$this;
????}

????//?設(shè)置樂觀鎖原始條件字段名列表
????function?setOptimisticRaw(string?$optimisticConditionRaw,?array?$bindings?=?[])
????{
????????$this->optimisticConditionRaw?=?$optimisticConditionRaw;
????????$this->bindings?=?$bindings;
????????return?$this;
????}}

Instructions for using optimistic lock

1. Use

/**
*?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;}

in the model (Models) or model parent class. 2. Usage method:

?$ord?=?Order::find(1);
?$ord->payment_status?=?1;
?if(!$model->setOptimistic(['payment_status'?=>?0]))->save())
???throws?new?Exception('訂單已付過款了');

or use the original SQL method:

?$ord?=?Order::find(1);
?$ord->payment_status?=?1;
?if(!$model->setOptimisticRaw('payment_status?=??',[1]))->save())
???throws?new?Exception('訂單已付過款了');

If the same object is small If multiple updates are involved, the lock condition can be cleared

$ord->clearOptimistic();

The above is the implementation method of optimistic locking, which is commonly used and necessary in actual development.

Recommended learning: "laravel video tutorial"

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