Grab A Random Record From The Database

I recently learned of a clever way to grab a random record for a particular model from the database. This is handy if you are poking around in the database to see what some records look like.

Order the records for that table randomly and then grab the first.

Event.order('random()').first

This grabs a random Event record from the events table.

Note, however, that for Rails 6+, this approach won't work. Because of some extra safety measures around executing raw SQL, you'll instead have to write the above as:

Event.order( Arel.sql('random()') ).first

This uses Arel.sql to mark 'random()' as a known-safe string of SQL.

Because we are explicitly passing a string that represents a known-safe function call, this is fine. Take care to not pass any user-generated SQL in a scenario like this unless you know what you're doing.

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