The operation delete not working ($inp['__dbid'] order mismatch)

[CharlesKumar]

I experienced an issue after deleting a few records, inserting a few and again tried to delete

nothing happened...

inspected through the code

 private function tweak($input){
      $counter = 0;
      foreach($input as $inp){
        array_push($this->uids, $counter);
        $inp['__dbid'] = $counter;
        $this->data[] = $inp;
        $counter++;
      }
      $this->rawd = $this->data;
    }

The delete operation is based on ['__dbid'] which is based on $counter created in tweak function

So I temporarily reordered using array_values in delete function (like below)

 public function delete(){
      $this->base->tbdata['data'] = array_values($this->base->tbdata['data']);
      foreach($this->data as $d) {
        unset($this->base->tbdata['data'][$d['__dbid']]);
      }
      $this->base->tbdata['data'] = array_values($this->base->tbdata['data']);
      $this->base->_saveData();
      return true;
    }

kindly look through this when you go through crunchdb

[cybrox]

Thanks a lot for reporting this issue and providing such detailed information!

I'll see if I can reproduce this, as soon as possible. - I think I'll be able to look into it by mid next week.

[cybrox]

Hi, sorry for the late reply.

I ran a little test script and was able to reproduce your issue:

$cdb->table('names')->create());
$cdb->table('names')->count());

$cdb->table('names')->insert(array("name" => "Name A"));
$cdb->table('names')->insert(array("name" => "Name B"));
$cdb->table('names')->insert(array("name" => "Name C"));
$cdb->table('names')->select(["name", "==", "Name A"])->delete();
$cdb->table('names')->select(["name", "==", "Name B"])->delete();
$cdb->table('names')->select(["name", "==", "Name C"])->delete();

// Database should be empty but contains "C"
$cdb->table('names')->select('*')->fetch();
$cdb->table('names')->count());

$cdb->table('names')->drop();

Thank you for providing a fitting solution. Although I don't think re-aligning the table twice is necessary. The bug is only caused by shifts from previous deletes, so using array_values() once after the delete (unset) operation should suffice.

      // working delete();
      foreach($this->data as $d) {
        unset($this->base->tbdata['data'][$d['__dbid']]);
      }
      $this->base->tbdata['data'] = array_values($this->base->tbdata['data']);
      $this->base->_saveData();
      return true;

In Conclusion, if you want, you can file a PR to have these changes merged into the library under your name. Otherwise, I'll just commit them manually and reference this issue :)

---

For reference:
Another method of solving this, would be modifying _saveData instead, so the table is aligned after every mutation. I don't think there's any other use case than the delete operation that requires this fix, though, so your solution should work fine

$aligned_table = array("data" => array_values($this->tbdata["data"]));
file_put_contents($this->tbpath, json_encode($aligned_table));

[CharlesKumar]

Hi Sven,

thanks for getting into this and also for keeping this nice project (still a unique project in this category json database system)

Although I've been using github for years yet to do a PR

next time i'll do