106 lines
1.9 KiB
Markdown
106 lines
1.9 KiB
Markdown
---
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title: "Phoenix: Ecto migrations"
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category: Elixir
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weight: -1
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updated: 2020-02-23
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---
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### Creating
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```bash
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$ mix ecto.gen.migration update_posts_table
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creating priv/repo/migrations/20160602085927_update_posts_table.exs
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···
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```
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```bash
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$ mix ecto.migrate
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$ mix ecto.rollback
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```
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Creates a migration (no models).
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### Creating models
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```bash
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$ mix phoenix.gen.model Message messages user_id:integer content:text
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```
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This is only for Phoenix 1.2 or older; models aren't available in Phoenix 1.3+.
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### Creating context
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```bash
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$ mix phx.gen.context Images Album albums title:string subtitle:string privacy:string
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```
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## Migration functions
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### Creating tables
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```elixir
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create table(:documents) do
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add :title, :string
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add :title, :string, size: 40
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add :title, :string, default: "Hello"
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add :title, :string, default: fragment("now()")
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add :title, :string, null: false
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add :body, :text
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add :age, :integer
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add :price, :float
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add :price, :float
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add :price, :decimal, precision: 10, scale: 2
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add :published_at, :utc_datetime
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add :group_id, references(:groups)
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add :object, :json
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timestamps # inserted_at and updated_at
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end
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create_if_not_exists table(:documents) do: ... end
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```
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### Other operations
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```elixir
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alter table(:posts) do
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add :summary, :text
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modify :title, :text
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remove :views
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end
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```
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```elixir
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rename table(:posts), :title, to: :summary
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rename table(:posts), to: table(:new_posts)
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```
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```elixir
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drop table(:documents)
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drop_if_exists table(:documents)
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```
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```elixir
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table(:documents)
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table(:weather, prefix: :north_america)
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```
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### Indices
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```elixir
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create index(:posts, [:slug], concurrently: true)
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create unique_index(:posts, [:slug])
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drop index(:posts, [:name])
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```
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### Execute SQL
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```elixir
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execute "UPDATE posts SET published_at = NULL"
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execute create: "posts", capped: true, size: 1024
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```
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## References
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- [Ecto.Migration](http://devdocs.io/phoenix/ecto/ecto.migration)
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