Then it configures our otp_app name, and the adapter – Postgres, in our case. It begins by defining the repository module. defmodule Hello.Repo do use Ecto.Repo, otp_app : :hello, adapter : end Phoenix generated it for us in lib/hello/repo.ex, and this is what it looks like. Our Hello.Repo module is the foundation we need to work with databases in a Phoenix application. Notice that we do get an id column as our primary key by default, even though it isn't listed as a field in our migration. Updated_at | timestamp without time zone | not null Inserted_at | timestamp without time zone | not null Id | bigint | not null default nextval('users_id_seq'::regclass) defmodule do use Ecto.Migration def change do create table ( :users ) do add :name, :string add :email, :string add :bio, :string add :number_of_pets, :integer timestamps ( ) end end endĪnd here's what that translates to in the actual users table. It will also add timestamp columns for inserted_at and updated_at which come from the timestamps/1 function. If we take a look at the migration generated by in priv/repo/migrations/, we'll see that it will add the columns we specified. Public | users_id_seq | sequence | postgres Public | schema_migrations | table | postgres You are now connected to database "hello_dev" as user "postgres". Ecto assumes that we want an integer column called id as our primary key, so we should see a sequence generated for that as well. If we log in to our database server, and connect to our hello_dev database, we should see our users table. Mix assumes that we are in the development environment unless we tell it otherwise with MIX_ENV=prod mix ecto.migrate. With our files in place, let's follow the instructions and run our migration: $ mix ecto.migrate Next, a migration file was generated inside priv/repo/migrations/ which will create our database table that our schema maps to. First, we have a user.ex file, containing our Ecto schema with our schema definition of the fields we passed to the task. Remember to update your repository by running migrations:Ī couple of files were generated with this task. $ mix User users name:string email:string \ Let's generate a User schema with name, email, bio, and number_of_pets fields. Ecto schemas are a way for us to specify how Elixir data types map to and from external sources, such as database tables. Once we have Ecto and PostgreSQL installed and configured, the easiest way to use Ecto is to generate an Ecto schema through the task. For instructions on switching to MySQL, please see the Using MySQL section. The introductory guides cover how to get your first application up and running. This guide assumes that we have generated our new application with Ecto integration and that we will be using PostgreSQL. Please check out Ecto's README for general information. You can pass the -database option to change or -no-ecto flag to exclude this.Įcto also provides support for other databases and it has many learning resources available. Newly generated Phoenix projects include Ecto with the PostgreSQL adapter by default. Phoenix uses Ecto to provide builtin support to the following databases: Before we jump into building database-backed web features, we're going to focus on the finer details of Ecto to give a solid base to build our web features on top of. In the Elixir ecosystem, we have Ecto to enable this. Most web applications today need some form of data validation and persistence. Requirement: This guide expects that you have gone through the introductory guides and got a Phoenix application up and running.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |