How to select record by distinct column in Rails3?

问题

There is one model named Book, I want to get all books, but all results have distinct column named 'author', how to do this ? thanks!

回答1:

May be by:

Book.select("DISTINCT(author)")

for more read this: Active Record Query Interface

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Edit

You can try: find_by_sql as

Book.find_by_sql("select * from books group by author")

来源：https://stackoverflow.com/questions/5701911/how-to-select-record-by-distinct-column-in-rails3