Differences from other ORMs

NoBrainer breaks a couple of established patterns to provide a consistent API with semantics as precise as possible.

• RethinkDB does not support transactions, so you need to be in control of when a database write happens. NoBrainer never autosaves a model behind the scenes.
• has_many associations are read-only. Writable has_many associations are leaky abstractions and are thus not implemented to keep sane semantics. Therefore there is no has_and_belongs_to_many associations. Read the Associations section on how to create your own join table.
• Returning false in a before_* callback does not halt the chain. If you want to abort the chain, you must be explicit by raising an exception or adding an error to the model in the case of a before_validation callback.
• The latest order_by() wins when chaining queries.
• Specifying types on fields introduces safe type casting and performs automatic validations in models and queries.
• instance.reload will also clear all the instance variable of an instance and call initialize() again.
• Uniqueness validators can leverage distributed locks to provide race-free semantics. This feature is crucial when using sharded databases such as RethinkDB as secondary indexes do not provide uniqueness guarantees.
• Declaring an index with multi => true does not change the behavior of queries, unlike Mongoid. When the any keyword is used (e.g. Post.where(:tags.any => 'programming')), NoBrainer uses a multi index if declared, but otherwise falls back to generating a suitable RQL code.