18 profiles \ # table name
26 defmodule Myapp.Accounts.User do
32 field :password, virtual: true
52 | `{:array, inner_type}` |
61 def changeset(user, params \\ :empty) do
63 |> Ecto.Changeset.change # basic casting to changeset
66 |> cast(params, ~w(name email), ~w(age)) # params to Changeset
68 |> validate_format(:email, ~r/@/)
70 |> validate_inclusion(:age, 18..100)
71 |> validate_exclusion(:role, ~w(admin superadmin))
72 |> validate_subset(:pets, ~w(cat dog parrot whale))
74 |> validate_length(:body, min: 1)
75 |> validate_length(:body, min: 1, max: 160)
76 |> validate_length(:partners, is: 2)
78 |> validate_number(:pi, greater_than: 3)
79 |> validate_number(:pi, less_than: 4)
80 |> validate_number(:pi, equal_to: 42)
82 |> validate_change(:title, fn _, _ -> [])
83 |> validate_confirmation(:password, message: "does not match")
85 |> unique_constraint(:email)
86 |> foreign_key_constraint(:post_id)
87 |> assoc_constraint(:post) # ensure post_id exists
88 |> no_assoc_constraint(:post) # negative (useful for deletions)
96 changeset.errors #=> [title: "empty"]
98 changeset.changes #=> %{}
99 changeset.params[:title]
101 changeset.required #=> [:title]
102 changeset.optional #=> [:body]
108 changeset #(or model)
109 |> change(title: "New title")
110 |> change(%{ title: "New title" })
111 |> put_change(:title, "New title")
112 |> force_change(:title, "New title")
113 |> update_change(:title, &(&1 <> "..."))
115 |> delete_change(:title)
116 |> merge(other_changeset)
118 |> add_error(:title, "empty")
124 get_change(changeset, :title) #=> "hi" (if changed)
125 get_field(changeset, :title) #=> "hi" (even if unchanged)
127 fetch_change(changeset, :title) #=> {:ok, "hi"} | :error
128 fetch_field(changeset, :title) #=> {:changes | :model, "value"} | :error
137 Repo.get_by(User, email: "john@hello.com") #=> %User{} | nil
145 changeset |> Repo.update
146 changeset |> Repo.insert
147 changeset |> Repo.insert_or_update
152 |> Ecto.Changeset.change(%{name: "hi"})
162 where: p.title == "Hello",
163 where: [state: "Sweden"],
169 order_by: [c.name, c.title],
170 order_by: [asc: c.name, desc: c.title],
172 preload: [:comments],
173 preload: [comments: {c, likes: l}],
175 join: c in assoc(c, :comments),
176 join: p in Post, on: c.post_id == p.id,
180 select: {p.title, p.description},
181 select: [p.title, p.description],
193 Repo.update_all(Post, set: [title: "Title"])
194 Repo.update_all(Post, inc: [views: 1])
197 ### Chaining `_all` with queries
200 from(p in Post, where: p.id < 10)
201 |> Repo.update_all(...)
203 from(p in Post, where: p.id < 10)