Rails Console find users by array of ids

Seth picture Seth · Jan 29, 2014 · Viewed 64.9k times · Source

So I have an array of user ids. Is there a way in rails console to query all of these user's with the array

something like

ids = [1, 2, 3, 4]

users = User.find(ids)

and have it return all 4 users?

Answer

Grant Birchmeier picture Grant Birchmeier · Jan 29, 2014

For an array, you can use one of these:

# Will raise exception if any value not found
User.find( [1,3,5] )

# Will not raise an exception
User.find_all_by_id( [1,3,5] ) # Rails 3
User.where(id: [1,3,5])        # Rails 4

If you happen to be using a range, you can use these:

# Will raise exception if any value not found
User.find((1..4).to_a)   #same as User.find([1,2,3,4])

# Will not raise an exception
User.find_all_by_id(1..4)  # Rails 3
User.where(id: 1..4)       # Rails 4

As @diego.greyrobot notes in a comment, a range causes a SQL BETWEEN clause, whereas an array causes a SQL IN clause.

Don't use User.find_by_id() -- It will only return one record, no matter how may IDs you pass in.