Transitioning from php to python/pylons/SQLAlchemy -- Are ORMs the standard now?

Question

Should I invest a lot of time trying to figure out an ORM style implementation, or is it still common to just stick with standard SQL queries in python/pylons/sqlalchemy?

Answer 1

ORMs are very popular, for several reasons -- e.g.: some people would rather not learn SQL, ORMs can ease porting among different SQL dialects, they may fit in more smoothly with the mostly-OOP style of applications, indeed might even ease some porting to non-SQL implementations (e.g, moving a Django app to Google App Engine would be much more work if the storage access layer relied on SQL statements -- as it relies on the ORM, that reduces, a bit, the needed porting work).

SQLAlchemy is the most powerful ORM I know of for Python -- it lets you work at several possible levels, from a pretty abstract declarative one all the way down to injecting actual SQL in some queries where your profiling work has determined it makes a big difference (I think most people use it mostly at the intermediate level where it essentially mediates between OOP and relational styles, just like other ORMs).

You haven't asked for my personal opinion in the matter, which is somewhat athwart of the popular one I summarized above -- I've never really liked "code generators" of any kind (they increase your productivity a bit when everything goes smoothly... but you can pay that back with interest when you find yourself debugging problems [[including performance bottlenecks]] due to issues occurring below the abstraction levels that generators strive to provide).

When I get a chance to use a good relational engine, such as PostgreSQL, I believe I'm overall more productive than I would be with any ORM in between (incuding SQLAlchemy, despite its many admirable qualities). However, I have to admit that the case is different when the relational engine is not all that good (e.g., I've never liked MySQL), or when porting to non-relational deployments is an important consideration.

So, back to your actual question, I do think that, overall, investing time in mastering SQLAlchemy is a good idea, and time well-spent.

Answer 2

If you have never use an ORM like SqlAlchemy before, I would suggest that you learn it - as long as you are learning the Python way. If nothing else, you will be better able to decide where/when to use it vs plain SQL. I don't think you should have to invest a lot of time on it. Documentation for SQLAlchemy is decent, and you can always ask for help if you get stuck.