Question

有没有办法将int列中的值减去1？我有一个按钮，单击它时会调用一个函数来保存表中的数据，但我想知道如何减去一个使用yii 2的数据库中的数字我已经尝试了下面的代码，但它没有任何效果。有人能帮助我如何在yii 2中进行数学运算吗？

public static function AddSubject($subjectid, $clientid){
    $subject = ActiveCurriculum::findOne(['subjectid' => $subjectid]);

    $activesubject = new ActiveSubject();
    $activesubject->clientid = $clientid;
    $activesubject->subjectid = $subject->subjectid;
    $activesubject->subjectcode = $subject->subjectcode;
    $activesubject->days = $subject->days;
    $activesubject->time = $subject->time;
    $activesubject->section = $subject->section;
    $activesubject->room = $subject->room;
    $activesubject->units = $subject->units;
    $subject->units = $subject->units - 1; //this should subtract the number 
    //of slots by 1 but now it is not working.
    $activesubject->save();

    return true;

    //return static::findOne(['subjectid' => $subjectid]);
                //->where(['subjectid' => $subjectid]);

  }

Answer 1

当您对AR对象进行了一些更改并希望保存更改时，您应该执行->save()：

$subject->units = $subject->units - 1; 
$subject->save();

看起来你只是忘了那样做。

Answer 2

您可以使用以下内容大规模复制属性，然后保存新模型：

public static function AddSubject($subjectid, $clientid){

    $subject = ActiveCurriculum::findOne(['subjectid' => $subjectid]);

    $activesubject = new ActiveSubject();

    $activesubject->attributes = $subject->attributes;
    $activesubject->isNewRecord = true;

    $activesubject->clientid = $clientid;
    $activesubject->units = $activesubject->units - 1;

    return $activesubject->save();
}

在您的代码中，您从$subject模型中减去，但保存了$activesubject模型。

yii 2 Active Query中的数学运算

2 个答案: