数学运算在yii 2活动查询 - Math operation in yii 2 Active Query

Math operation in yii 2 Active Query

本文关键字：活动查询 yii 运算 | 更新日期: 2023-09-27

是否有一种方法可以在int列中减去一个值来表示1?我有一个按钮，当它被点击时，它会调用一个函数来保存表中的数据，但我想知道如何使用yii 2减去数据库中的数字，我已经尝试了下面的代码，但它没有效果。有人能教我怎么用yii做数学运算吗?

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]);
  }

当你在AR对象中做了一些更改并希望保存这些更改时，你应该执行->save():

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

看起来你只是忘记了。

您可以使用以下命令大量复制属性，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();
}

在你的代码中，你从$subject模型中减去，但你保存$activesubject模型。