TiDB is an open-source NewSQL database that supports Hybrid Transactional and Analytical Processing (HTAP) workloads. It is MySQL compatible and features horizontal scalability, strong consistency, and high availability.
I assumed using TiDB as a backend storage layer of Ruby on Rails application perhaps is a great way to manage storages into one place.
This post describes how to get started and how to use TiDB as backend of Ruby on Rails applications for developers.
Example source codes are available at rails-tidb in GitHub.
Setting up local TiDB server
Install tiup
$ curl --proto '=https' --tlsv1.2 -sSf https://tiup-mirrors.pingcap.com/install.sh | sh
Starting TiDB playground
$ tiup playground nightly
Then, we can connect to the TiDB instance just as connecting to MySQL.
mysql --host 127.0.0.1 --port 4000 -u root -p
Initialize Ruby on Rails application
$ ruby -v
ruby 2.7.0
$ rails -v
Rails 6.1.4
$ rails new tidb-rails --database=mysql --api
Add activerecord-tidb-adapter to Gemfile
$ bundle add activerecord-tidb-adapter --version "~> 6.1.0"
After creating a new app, edit config/database.yml
to configure connection settings to TiDB.
default: &default
adapter: tidb
encoding: utf8mb4
collation: utf8mb4_general_ci
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
host: 127.0.0.1
port: 4000
variables:
tidb_enable_noop_functions: ON
username: root
password:
development:
<<: *default
database: tidb_rails_development
No need to add additional database configurations to use TiDB. Itβs ready to use TiDB as a database of the Rails app!
Create a database
$ bundle exec rails db:create
Created database 'tidb_rails_development'
Created database 'tidb_rails_test'
Manipulate TiDB data through Rails app
Defining Model using rails g command.
$ bundle exec rails g model user email:string name:string gender:integer
...
$ vim ./db/migrate/20210826174523_create_users.rb # edit
db/migrate/20210826174523_create_users.rb
class CreateUsers < ActiveRecord::Migration[6.1]
def change
create_table :users do |t|
t.string :email, index: {unique: true}
t.string :name
t.integer :gender
t.timestamps
end
end
end
Then, apply database migration.
$ bundle exec rails db:migrate
== 20210826174523 CreateUsers: migrating ======================================
-- create_table(:users)
-> 0.1717s
== 20210826174523 CreateUsers: migrated (0.1717s) =============================
Launch Rails console to play with the app.
$ bundle exec rails c
Running via Spring preloader in process 13378
Loading development environment (Rails 6.1.4.1)
irb(main):001:0> 30.times.each { |i| User.create!(email: "user-#{i}@example.com", name: "user-#{i}", gender: i % 3) }
(1.2ms) select version()
TRANSACTION (0.8ms) BEGIN
User Create (93.5ms) INSERT INTO `users` (`email`, `name`, `gender`, `created_at`, `updated_at`) VALUES ('user-0@example.com', 'user-0', 0, '2021-08-26 17:50:40.661945', '2021-08-26 17:50:40.661945')
TRANSACTION (14.9ms) COMMIT
...
=> 30
irb(main):002:0> User.count
(8.9ms) SELECT COUNT(*) FROM `users`
=> 30
irb(main):003:0> User.first
User Load (5.8ms) SELECT `users`.* FROM `users` ORDER BY `users`.`id` ASC LIMIT 1
=> #<User id: 1, email: "user-0@example.com", name: "user-0", gender: 0, created_at: "2021-08-26 17:50:40.661945000 +0000", updated_at: "2021-08-26 17:50:40.661945000 +0000">
Summary
TiDB offers MySQL interfaces which can be used as backend database layers of Ruby on Rails applications.
We can use ActiveRecord ORM directly, or use activerecord-tidb-adpater, a lightweight extension of ActiveRecord that supports several rails versions, including 5.2, 6.1, and 7.0.
The activerecord-tidb-adapter provides compatible patches and some tidb-specific functions, such as Sequence.
Top comments (2)
Great introduction article.
Based on the document and
show collation
output from TiDB 5.1.1, TiDB does not supportutf8mb4_general_ci
.Then this database.yml may need to be updated as follows?
Character sets and collations supported by TiDB
docs.pingcap.com/tidb/stable/chara...
show collation
output from TiDB 5.1.1Yes. when
new_collations_enabled_on_first_bootstrap = true
is set, utf8mb4_general_ci is avaliable. I missed this tidb cluster setting.