What's the difference between the build and create methods in FactoryGirl?

Question

The Factory Girl introduction delineates the difference between FactoryGirl.build() and FactoryGirl.create():

# Returns a User inst         


        

Answer 1

The create() method persists the instance of the model while the build() method keeps it only on memory.

Personally, I use the create() method only when persistence is really necessary since writing to DB makes testing time consuming.

e.g.

I create users to authentication with create() because my authentication engine queries the DB.

To check if a model has an attribute the build() method will do because no DB access is required.

it{Factory.build(:user).should respond_to(:name)}

Update

"There is one exception that build actually 'creates' when you are building associations, i.e your association are no longer in memory but persisted. Keep that in mind" – Shakes