Last active
October 11, 2018 16:35
Star
You must be signed in to star a gist
ActiveRecord + PostgreSQL enums
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# require 'pg'; PG.connect(dbname: 'postgres').exec('create database josh_testing') # <-- uncomment to create the db (only needs to run once) | |
# ===== Setup ActiveRecord ===== | |
require 'active_record' | |
require 'logger' | |
ActiveRecord::Base.establish_connection adapter: 'postgresql', database: 'josh_testing' | |
ActiveRecord::Base.logger = Logger.new $stdout | |
ActiveSupport::LogSubscriber.colorize_logging = false | |
# ===== Migration ===== | |
ActiveRecord::Schema.define do | |
self.verbose = false | |
# reset db | |
drop_table :workers, if_exists: true | |
execute "drop type if exists worker_type;" | |
# create the type | |
execute "create type worker_type as enum ('person', 'script', 'model');" | |
# create the table | |
create_table :workers do |t| | |
t.column :type, :worker_type, null: false | |
end | |
end | |
# ===== Model ===== | |
class Worker < ActiveRecord::Base | |
# Rails convention is for the `type` column to be used for STI | |
# we aren't using STI and we have a type column, | |
# so we need to override the convention to use some nonexistant column | |
self.inheritance_column = :_sti_disabled | |
enum type: { | |
people: 'person', | |
scripts: 'script', | |
models: 'model', | |
} | |
end | |
# ===== Creating Data ===== | |
Worker.create! [ | |
{type: 'person'}, | |
{type: 'person'}, | |
{type: 'script'}, | |
{type: 'model' }, | |
] | |
# ===== Querying ===== | |
Worker.people.to_sql | |
# => "SELECT \"workers\".* FROM \"workers\" WHERE \"workers\".\"type\" = 'person'" | |
Worker.people | |
# => [#<Worker:0x00007f9684bf2558 id: 1, type: "people">, | |
# #<Worker:0x00007f9684bf2378 id: 2, type: "people">] | |
Worker.scripts | |
# => [#<Worker:0x00007f96868361b0 id: 3, type: "scripts">] | |
Worker.models | |
# => [#<Worker:0x00007f9684bf6180 id: 4, type: "models">] | |
# ===== Invalid Values ===== | |
# All three of these seem like strange behaviour to me, feels like it should just add a validation | |
Worker.new(type: 'something_else') rescue $! # => #<ArgumentError: 'something_else' is not a valid type> | |
Worker.new.valid? # => true | |
Worker.new.save rescue $! # => #<ActiveRecord::NotNullViolation: PG::NotNullViolation: ERROR: null value in column "type" violates not-null constraint\nDETAIL: Failing row contains (5, null).\n: INSERT INTO "workers" DEFAULT VALUES RETURNING "id"> | |
# We can address the last two with our own validation | |
Worker.validates :type, inclusion: { in: %w[person script model] } | |
Worker.new(type: 'something_else') rescue $! # => #<ArgumentError: 'something_else' is not a valid type> | |
w = Worker.new | |
w.valid? # => false | |
w.errors.full_messages # => ["Type is not included in the list"] | |
# >> D, [2018-10-11T11:35:22.832577 #55812] DEBUG -- : (3.7ms) DROP TABLE IF EXISTS "workers" | |
# >> D, [2018-10-11T11:35:22.834320 #55812] DEBUG -- : (1.5ms) drop type if exists worker_type; | |
# >> D, [2018-10-11T11:35:22.836611 #55812] DEBUG -- : (2.1ms) create type worker_type as enum ('person', 'script', 'model'); | |
# >> D, [2018-10-11T11:35:22.842889 #55812] DEBUG -- : (5.4ms) CREATE TABLE "workers" ("id" bigserial primary key, "type" worker_type NOT NULL) | |
# >> D, [2018-10-11T11:35:22.885089 #55812] DEBUG -- : ActiveRecord::InternalMetadata Load (0.5ms) SELECT "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2 [["key", "environment"], ["LIMIT", 1]] | |
# >> D, [2018-10-11T11:35:22.891333 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.892533 #55812] DEBUG -- : (0.2ms) COMMIT | |
# >> D, [2018-10-11T11:35:22.900873 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.902100 #55812] DEBUG -- : Worker Create (0.6ms) INSERT INTO "workers" ("type") VALUES ($1) RETURNING "id" [["type", "person"]] | |
# >> D, [2018-10-11T11:35:22.903688 #55812] DEBUG -- : (1.3ms) COMMIT | |
# >> D, [2018-10-11T11:35:22.904200 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.904931 #55812] DEBUG -- : Worker Create (0.3ms) INSERT INTO "workers" ("type") VALUES ($1) RETURNING "id" [["type", "person"]] | |
# >> D, [2018-10-11T11:35:22.906561 #55812] DEBUG -- : (1.4ms) COMMIT | |
# >> D, [2018-10-11T11:35:22.907113 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.908105 #55812] DEBUG -- : Worker Create (0.4ms) INSERT INTO "workers" ("type") VALUES ($1) RETURNING "id" [["type", "script"]] | |
# >> D, [2018-10-11T11:35:22.909961 #55812] DEBUG -- : (1.4ms) COMMIT | |
# >> D, [2018-10-11T11:35:22.910556 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.911279 #55812] DEBUG -- : Worker Create (0.3ms) INSERT INTO "workers" ("type") VALUES ($1) RETURNING "id" [["type", "model"]] | |
# >> D, [2018-10-11T11:35:22.913072 #55812] DEBUG -- : (1.5ms) COMMIT | |
# >> D, [2018-10-11T11:35:22.915092 #55812] DEBUG -- : Worker Load (0.3ms) SELECT "workers".* FROM "workers" WHERE "workers"."type" = $1 [["type", "person"]] | |
# >> D, [2018-10-11T11:35:22.916361 #55812] DEBUG -- : Worker Load (0.3ms) SELECT "workers".* FROM "workers" WHERE "workers"."type" = $1 [["type", "script"]] | |
# >> D, [2018-10-11T11:35:22.917269 #55812] DEBUG -- : Worker Load (0.3ms) SELECT "workers".* FROM "workers" WHERE "workers"."type" = $1 [["type", "model"]] | |
# >> D, [2018-10-11T11:35:22.918083 #55812] DEBUG -- : (0.2ms) BEGIN | |
# >> D, [2018-10-11T11:35:22.919092 #55812] DEBUG -- : Worker Create (0.6ms) INSERT INTO "workers" DEFAULT VALUES RETURNING "id" | |
# >> D, [2018-10-11T11:35:22.919416 #55812] DEBUG -- : (0.1ms) ROLLBACK |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment