Comment by blar | Hacker News Reader

Comment by blar | Hacker News Reader

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For the last three years or so, I've been telling anyone who asked that ORM is an antipattern, to be avoided at all costs. I've settled into wrapping all queries in classes, with any parameters exposed as public properties. The SQL is written inside the class, essentially in a template. When necessary, the generated query can change based on the values assigned to the properties. All the mechanics of how the query is executed and passed to the database get rolled up in the base class, with a public method that returns the dataset returned by execution. Then I just run the dataset through transformation functions to get the data structures I actually need - combining multiple result sets if necessary to build really complicated objects when I have to.

I've been building this approach for a couple years now, and I haven't regretted it for a minute. I don't have to fit my databases to the vagaries of the ORM layer, and I have full control over my queries. I NEVER want to go back to ORM :)

> I NEVER want to go back to ORM

Except that you just invented your own ORM.

Think about it: you are encapsulating SQL data into classes, in other words, mapping relational data to objects.

That's an ORM.

You've just broadened the definition of ORM so that any SQL abstraction layer in an OO language becomes an ORM.

That's a rather nonstandard usage.

ORM is "Object Relational Mapper".

If you are taking data out of a relational database and mapping it into objects, you are implementing an ORM.

Seems like I'm sticking to the exact definition of an ORM, aren't I?

> If you are taking data out of a relational database and mapping it into objects, you are implementing an ORM.

No, ORM is a particular approach to doing that; the query abstraction approach described upthread is closer to the DAO pattern, to which ORM is an alternative. People were using RDBMSs to provide a persistence layer for OO programs before ORM was a thing, but as you have broadened the term any use of an RDBMS to store/retrieve data used in an OO program would be "ORM".

Now you're the one using a nonstandard definition of ORM. Here is how Wikipedia defines it:

    Object-relational mapping (ORM, O/RM, and O/R mapping)
    in computer science is a programming technique for
    converting data between incompatible type systems
    in object-oriented programming languages.

"is a technique for" does not mean "includes every technique for".

Spearfishing is a technique for catching fish, but not every technique for catching fish is spearfishing.

I believe the difference here is that one is an ORM framework, while the other is just objects bound to a database.

ORM frameworks usually allow you to drop down to SQL. But then you're stuck in that terrible world of depending on poorly-documented and soon-to-be-deprecated (or already deprecated) internals. Which are pretty much guaranteed to not fit what you really need anyway. Then you have to bridge your hack objects with the "proper" ORM objects. Your crufty hack objects will probably never be seen as first-class citizens in ORM land, forever banished to edge case hell.

I think it's pretty clear that (s)he's talking about ActiveRecord.

I've used this pattern and I like it a lot (for the reasons you say) but I find I still spent way too much time on really mundane stuff... particularly table<-->object mapping if the database table has a lot of columns.

My current approach is:

1. I basically judge ORMs on how easily they allow me to use custom SQL. (ActiveRecord makes this pretty tolerable with find_by_sql) 2. Let the ORM handle as much CRUD and table<-->object mapping as possible 3. If I have complex SQL, I try to wrap it in an appropriate database object (view, sproc, function).

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