> I have a dream ... > I am happy to join with you today in what will go down in history as the > greatest demonstration of

bad design of Active Record.How do we get the `{id}`? The essential solutuion is UUID generated by a client. It allows API application to be stateless and scale it, use master-master replication for databases and feel yourself a modern guy.
If you have Postgres -— lucky you, feel free to use the built-in UUID data type and close this article. With MySQL the essential solution is [insert into users values(unhex(replace(uuid(),'-',''))...](https://mysqlserverteam.com/storing-uuid-values-in-mysql-tables/) MySQL team recommends updating our INSERT queries. With Active Record it is not really possible. For fetching UUIDs it recommends adding a virtual column -— this can be used.

If you design the application from ground up, you can use defferent fields for a binary and text representation of UUID, and reference them in different parts of an application, but I am bound to the legacy code.Here's the hack:

Step 1. Add a `private `$idText;` property

```php// convert UUID from text value to binary and store the text value in a private variable
// this is a workaround for lack of mapping in active record
['id','filter','skipOnError' => true, 'filter' => function($uuid) {       $this->idText = $uuid;       return pack("H*", str_replace('-', '', $uuid));      }], //now let's check if ID is taken ['id','unique','filter' => function(\yii\db\Query $q){ {
 
    $q->where(['id' => $this->getAttribute('id')]);
 
}], ``` First rule is a validator for an input. Second rule is a filter preparing UUID to be written in a binary format and keeping the text form for output. Third one is a validator running a query over the binary value generated by a filter.
 
> Note: I wrote `$this->getAttribute('id')`, `$this->id` returns a text form.
 
We can write a query to validate data, not to save it.

Step 3. Add getters```

Step 5. Use Object Relation Mapping in Yii 3 when it's available and write simple mapping instead.