Q

Ad-hoc Ecto queries made simple as snapping your fingers. It's easy to use and saves you time, and the intended use case is to make ad-hoc changes to records from Elixir interactive console easier.

But you'll do whatever you want to do with it, you're the boss. Just remember: with great power comes great responsibility.

Installation

defdepsdo[{:q,"~> 2.0"}]end

Configuration

config:q,ecto_repo: MyApp.Repo

Usage

NOTE: Everything below is the intended API, not everything may be implemented.

Querying with Q

# No conditions, fetches all records:users=Q.all(User)# Specify conditions any way you like:users=Q.all(User,name: "John")# orusers=Q.all(User,%{name: "John"}))# orusers=Q.all(User,%{"name"=>"John"})# You can also pass options to Ecto.Repo:users=Q.all(User,%{"name"=>"John"},timeout: :infinity)# Converts nil to "IS NULL" and assumes you know what you're doing:users=Q.all(User,deleted_at: nil)# Allows to query for single recordsuser=Q.one(User,name: "John")user=Q.one(User,%{id: 23})# or use first to fetch first of many recordsuser=Q.first(User,name: "John")

Q.one/2 and Q.first/2 have also ! versions Q.one! and Q.find! that will raise Ecto.NoResultsError if no record is found.

Advanced querying and scopes

Q can use, return and chain Ecto queries with Q.where:

query=Q.where(User,name: "John",deleted_at: nil)users=Q.all(query)# you can also use MyApp.Repo.all() with the query# refining queries:filtered_query=Q.where(query,age: 23)filtered_users=Q.all(filtered_query)# you can also use Ecto to refine query further and use features Q does not support (yet):importEcto.Query,only: [from: 2]sorted_query=query|>from(uinfiltered_query,order_by: [asc: u.age],limit: 5)

Updating records

user=Q.first(User,name: "John")# this calls User.chaneset/2 implicitly{:ok,updated_user}=Q.update(user,%{name: "Jane"})# or you can specify a custom changeset function:{:ok,updated_user}=Q.update(user,%{name: "Jane"},&User.registration_changeset/2)# or use the ! version if you want to raise on error / receive record not wrapped in tupleupdated_user=Q.update!(user,%{name: "Jane"},&User.registration_changeset/2)

Deleting records

You can delete single records, list of records, or records returned by query:

:ok=Q.delete(user):ok=Q.delete([user1,user2]):ok=Q.delete(Q.where(User,name: "John"))

Transactions

Use Q.begin() and Q.commit() or Q.rollback() to use transactions.

Q.begin()Q.delete(user)Q.rollback()# one user was saved today!