Re:What ORMs have taught me: just learn SQL
by Silhouette on Monday August 04, 2014 @08:04PM
(#8134794)
However, the downside of this is that it only works as long as whatever you need from your database is the lowest common denominator of database features.
This can be an overriding practical objection to every ORM I've encountered so far.
To give an example I've run into several times, Postgres offers several levels of transaction isolation. The more isolated levels offer stronger guarantees, but you also need to be able to recover and retry if a transactions fails a serialization condition the first time. These levels determine how interactions work with related tools like explicit locking, SELECT FOR UPDATE, and so on.
In least common denominator ORM world, you're lucky if you get any serious control over this kind of thing at all. If you actually have a use case that requires precision here -- and sometimes you do even in surprisingly simple use cases, such as needing to allocate new IDs in an increasing, guaranteed contiguous sequence in Postgres -- then this stuff matters.
Writing longhand SQL queries is a pain for several obvious reasons, but it's still better than using an ORM and finding it doesn't support a feature you need or, worse, it does things implicitly and sometimes gets them wrong.
This can be an overriding practical objection to every ORM I've encountered so far.
To give an example I've run into several times, Postgres offers several levels of transaction isolation. The more isolated levels offer stronger guarantees, but you also need to be able to recover and retry if a transactions fails a serialization condition the first time. These levels determine how interactions work with related tools like explicit locking, SELECT FOR UPDATE, and so on.
In least common denominator ORM world, you're lucky if you get any serious control over this kind of thing at all. If you actually have a use case that requires precision here -- and sometimes you do even in surprisingly simple use cases, such as needing to allocate new IDs in an increasing, guaranteed contiguous sequence in Postgres -- then this stuff matters.
Writing longhand SQL queries is a pain for several obvious reasons, but it's still better than using an ORM and finding it doesn't support a feature you need or, worse, it does things implicitly and sometimes gets them wrong.