如何在Yii中保存数据并确保正确保存？

Question

Example: we have test table, which has 3 columns: id, watchers, title. We have a code:

$test = Test::model()->findByPk(1);
echo $test->watchers; // 0
$test->title = 'another';
$test->save();

When we call save() ir generates sql query like "UPDATE test SET title='another', watchers='0' WHERE id='1'" . SO, seams like everything is okay. But the problem is that if some another process will update watchers variable in the time between findByPk and save in current script, the code will generate wrong value. So:

$test = Test::model()->findByPk(1);
echo $test->watchers; // 0
$test->title = 'another';
//HERE WE HAVE A CODE WHICH PERFORMS FOR 1 SECOND. MEANWHILE ANOTHER PROCESS
// UPDATES TABLE WITH WATCHERS = 1
$test->save();

So, this code will save record's watchers field back to 0. How to overcome this? Why Yii ORM doesn't save only changed values? Why it tries to save all values? Thank you.

Answer 1

Since you get each value in $test , so when you do $test->save(); every attribute gets saved with new record or the previous value it contained.

When you query $test = Test::model()->findByPk(1); then $test->watchers; will be the same value which was there when you executed the query, this value will only change (if the value of watchers was changed by another update query) when you do another select query. Hope that makes sense :P

You can try the following update method :

Test::model()->updateByPk(1, array(
                'title' => 'another'
            ));

Which will execute the following query:

UPDATE `test` SET `title`=:yp0 WHERE `test`.`id`=1.
Bound with :yp0='another'

Answer 2

I would tackle the issue as such:

$test = Test::model()->findByPk(1);
$test->title = 'another';

/*according to the api the second parameter only saves the columns 
  that are mentioned in the array. In this case it will save just the
  title
*/

$test->save(true,array('title')); 

{or}

 $test = Test::model()->findByPk(1);
    $test->title = 'another';

    /*according to the api the parameter only saves the columns 
      that are mentioned in the array. In this case it will save just the
      title
    */

    $test->saveAttributes(array('title')); 

Answer 3

As for me, the best solution is to inherit and rewrite the save() method and do it's behaviour the same as it is in Yii2 (getDirtyAttributes() method). W must compar eattributes to fetched from the db attributes and save only those ones, which were modified. I've successfully implemented this and can cinfirm it works.