Question

I’m setting up a custom query that uses a range of OR statements in conjunction with BETWEEN statements and a final GROUP BY id HAVING COUNT(*) >= #{tolerance}. Not to mention INNER and LEFT join operations.

I would assume that it would not be possible to setup using active record. So I used the Model.connection.select_all() command to fire a query. This works, but how do I not map all of the rows to that specific model?

Answer 1

Rails is pretty powerful especially if you are using Rails 3 & ARel. So I wouldn’t be surprised if you actually could write your query using rails.

However, there will always be times when writing raw SQL is desired.

To do that, instead of Model.connection use Model.find_by_sql(QUERY_STRING).

This way the query will get parsed for you automatically just make sure you only select "model.*"