Geoff Wozniak has written up a post on the "Curried lambda" site sharing his opinion on ORMs (object relational mappers) for working with databases and how, after using them in his own development work, that they're a good side benefit but shouldn't replace knowing SQL.

I've come to the conclusion that, for me, ORMs are more detriment than benefit. In short, they can be used to nicely augment working with SQL in a program, but they should not replace it.

[...] Neward, in his well known essay, lays out many cogent reasons why ORMs turn into quagmires. In my experience, I've had to deal directly with a fair number of them: entity identity issues, dual-schema problem, data retrieval mechanism concern, and the partial-object problem. I want to talk briefly about my experiences with these issues and add one of my own.

He breaks the rest of the article up into several sections, for each sharing some of his own experiences with the feature and how it could be resolved using other query methods:

• Partial objects, attribute creep, and foreign keys
• Data retrieval
• Dual schema dangers
• Identities
• Transactions

He ends the post with a look forward, thinking about where he'll end up, mentioning stored procedures, queries as APIs and how "easy" isn't always best when it comes to ORMs.