如何在Yii2中实现mysql记录锁定

Question

I want to implement record locking functionality in my Yii2 application.

If one user opens update link/record (Ex. http://localhost/myproject/backend/web/user/update/1 ) then another user cannot able to access thislink and user will get an ALERT message saying " This record already opened by another user ". So the record/page should lock for another user. (Same like MS Excel locking)

Once first user finishes and leaves from that record/page then it should unlock and another user can read/update that data.

So how can I use mysql database locking mechanism here in Yii2 active records or is there any other way to implement this.

Any help would be appreciated.

Answer 1

It's called Optimistic Locking and described in official docs . Here is an example of implementation:

// ------ view code -------

use yii\helpers\Html;

// ...other input fields
echo Html::activeHiddenInput($model, 'version');


// ------ controller code -------

use yii\db\StaleObjectException;

public function actionUpdate($id)
{
    $model = $this->findModel($id);

    try {
        if ($model->load(Yii::$app->request->post()) && $model->save()) {
            return $this->redirect(['view', 'id' => $model->id]);
        } else {
            return $this->render('update', [
                'model' => $model,
            ]);
        }
    } catch (StaleObjectException $e) {
        // logic to resolve the conflict
    }
}

Answer 2

You can add column locked_by_user to your table and when someone is requested update action you check locked_by_user column if it is set or not. If not, set it to the user_id who is request update action first. Also you need to be concerned about reseting locks . And consider cases when user just can close the browser window and then record will be locked until he makes any action like save record or cancel editing .