-
wherereturns anActiveRecord::Relation(not an array, even though it behaves much like one), which is a collection of model objects. If nothing matches the conditions, it simply returns an empty relation. -
find(and its related dynamicfind_by_columnnamemethods) returns a single model object. If nothing is found, anActiveRecord::RecordNotFoundexception is raised (but not with the dynamicfind_by_methods).While
findcan return an Array of records—not a Relation—if given a list of IDs, usingwhereis preferred since Rails 3. Many similar uses offindare now deprecated or gone entirely.
So yes, if you only want and expect a single object, using find is easier, as otherwise you must call Model.where.first.
Note that old-style hash options to find and many dynamic find_ methods are deprecated as of Rails 4.0 (see relevant release notes).