如何在 Laravel 4 中使用 Eloquent 模型增加一列
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/16597426/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to increment a column using Eloquent Model in Laravel 4
提问by Abishek
I am not sure how to increment the value in a column using Eloquent Model in Laravel 4? This is what I currently have and I am not sure how correct is this.
我不确定如何在 Laravel 4 中使用 Eloquent 模型增加列中的值？这是我目前拥有的，我不确定这有多正确。
$visitor = Visitor::where('token','=','sometoken')->first();
if(isset($visitor)){
$visitor->increment('totalvisits');
}else{
Visitor::create(array(
'token'=>'sometoken',
'totalvisits'=>0
));
}
With Query Builder we could do it using
使用 Query Builder 我们可以使用
DB::table('visitors')->increment('totalvisits');
回答by Abishek
Looks like the code that I posted worked after all
看起来我发布的代码毕竟有效
$visitor = Visitor::where('token','=','sometoken')->first();
if(isset($visitor)){
$visitor->increment('totalvisits');
}else{
Visitor::create(array(
'token'=>'sometoken',
'totalvisits'=>0
));
}
回答by Jason Lewis
Prior to a fix a few weeks agothe incrementmethod actually fell through to the query builder and would be called on the entire table, which was undesirable.
在几周前修复之前，该increment方法实际上落入了查询构建器，并将在整个表上调用，这是不可取的。
Now calling incrementor decrementon a model instance will perform the operation only on that model instance.
现在在模型实例上调用increment或decrement将仅在该模型实例上执行操作。
回答by malhal
Laravel 5 now has atomic increment:
Laravel 5 现在具有原子增量：
public function increment($column, $amount = 1, array $extra = [])
{
if (! is_numeric($amount)) {
throw new InvalidArgumentException('Non-numeric value passed to increment method.');
}
$wrapped = $this->grammar->wrap($column);
$columns = array_merge([$column => $this->raw("$wrapped + $amount")], $extra);
return $this->update($columns);
}
which essentially works like:
它的工作原理如下：
Customer::query()
->where('id', $customer_id)
->update([
'loyalty_points' => DB::raw('loyalty_points + 1')
]);
Below is old answer for Laravel 4 where the built-in increment was a seperate select and then update which of course leads to bugs with multiple users:
下面是 Laravel 4 的旧答案，其中内置增量是一个单独的选择，然后更新这当然会导致多个用户的错误：
If you'd like to accurately count your visitors by ensuring the update is atomic then try putting this in your Visitor model:
如果您想通过确保更新是原子性的来准确计算访问者的数量，请尝试将其放入访问者模型中：
public function incrementTotalVisits(){
// increment regardless of the current value in this model.
$this->where('id', $this->id)->update(['totalVisits' => DB::raw('last_insert_id(totalVisits + 1)')]);
//update this model incase we would like to use it.
$this->totalVisits = DB::getPdo()->lastInsertId();
//remove from dirty list to prevent any saves overwriting the newer database value.
$this->syncOriginalAttribute('totalVisits');
//return it because why not
return $this->totalVisits;
}
I'm using it for a change tag system but might work for your needs too.
我将它用于更改标签系统，但也可能满足您的需求。
Does anyone know what to replace the "$this->where('id',$this->id)" with because since dealing with $this Visitor it should be redundant.
有谁知道用什么来替换 "$this->where('id',$this->id)" 因为因为处理 $this Visitor 它应该是多余的。
