Intro to Ecto
Ecto is the specific component for interacting with databases in the Elixir language. It supports mosts used database systems, the default being PostgreSQL, but Oracle, MySQL, SQLite, and MongoDB are also available. I recently started to work on Elixir for some project and here’s a short syntax sum-up for using Ecto in your web apps.
# Auto create models
mix phx.gen.model Account accounts user_id:integer first_name:string last_name:string
mix ecto.gen.migration create_table
creating priv/repo/migrations/20171020086542_create_table.exs
# Apply migration
mix ecto.migrate
# Rollback last migration
mix ecto.rollback
And here’s the Ecto syntax for managing data structures (DDL only).
# Creating a table
create table(:users) do
add :first_name, :string
add :last_name, :string, size: 40
add :username, :string, default: "Default"
add :creation_date, :string, default: fragment("now()")
add :ref_if, :string, null: false
add :description, :text
add :age, :integer
add :eur_price, :float
add :btc_price, :float, precision: 10, scale: 2
add :last_conn, :datetime
add :group_id, references(:groups)
add :object, :json
timestamps # inserted_at and updated_at
end
create_if_not_exists table(:users) do: ... end
# Altering a table
alter table(:users) do
add :intro, :text
modify :username, :text
remove :age
end
rename table(:users), :intro, to: :introduction
rename table(:users), to: table(:accounts)
# Dropping a table
drop table(:users)
drop_if_exists table(:users)
# Execute arbitrary SQL statements
execute "UPDATE users SET username = 'Def'"
execute create: "users", capped: true, size: 1024
# Create Indexes
create index(:users, [:first_name, :last_name], concurrently: true)
create unique_index(:users, [:username])
drop index(:users, [:first_name])