mtimokhin · HackerTrans

11 ปีที่แล้วdiscuss

Even in PHP (no named arguments):

    class Route
    {
       const RECURSIVE     = true;
       const NON_RECURSIVE = false;

       public function __construct($pattern, $recursive = Route::NON_RECURSIVE) {
         // ...
       }
     }
     $route = new Route($pattern, Route::RECURSIVE);

mtimokhin

12 ปีที่แล้วdiscuss

I think, the problem is in all-or-nothing approach when discussing that topic. It's always "abstract pure SQL" vs "abstract pure ORM", but I think the solution is in reasonable compromise between them.

First, it's definitely bad idea to write ORM that works with absolutely any database schema. If you accept some limitations in schema design (and some in model layer too), you can really benefit in more simple ORM design.

For instance, you can eliminate partial load at all, breaking stored entities into separate aspects in separate tables and using some tricks for fetching associations (see below).

Second, ORM should be as lightweight as possible, so you can really use it and not fight it.

There are things that just should not be used in ORM, if we don't want to solve some complicated performance problems. I believe, it's really bad idea to use auto-generated SQL JOINs on ORM side, it's very hard to control and optimize them. There is simple and clever solution by Jakub Vrana (https://www.facebook.com/jakubvrana/posts/415359675151430), that works really good if implemented carefully on ORM side. When you really need JOIN, you can use VIEW on database schema side or (better) use some kind of denormalization.

You can optimize VIEW on SQL side, you can move from views to denormalization without breaking model layer etc.

Using stored code on SQL side is good, you can maintain your database without any special client tools or code, and you could automate a lot of denormalization using triggers.

We have some slides (in Russian, sorry) on this topic here http://www.slideshare.net/interlabs-ru/model-patterns and here http://www.slideshare.net/interlabs-ru/sustainable-schema and implemented lightweight proprietary ORM (in PHP) based on principles above, possible open it later.

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