为什么我在此 Ecto 查询中收到未绑定的变量消息？

Question

嘿，我正在尝试进行查询，我的代码如下所示：

  def show(conn, _params) do
user = Guardian.Plug.current_resource(conn)
team = Web.get_team!(user.team.id)

score_query =
  from(
    u in User,
    where: u.team.id == team.id,
    select: sum(u.score)
  )

team_score = Repo.all(score_query)

IO.puts("score")
IO.inspect(team_score)

conn |> render("team.json", team: team)

当我尝试运行它时，我收到一条错误消息：

** (Ecto.Query.CompileError) unbound variable `team` in query

但为什么是未绑定的？我该如何解决它，为什么会这样？

Answer 1

你应该pin (^) team.id:

score_query =
  from(
    u in User,
    #                   ⇓ HERE
    where: u.team.id == ^team.id,
    select: sum(u.score)
  )

根据Ecto.Query documentation：

External values and Elixir expressions can be injected into a query expression with ^:
def with_minimum(age, height_ft) do
  from u in "users",
    where: u.age > ^age and u.height > ^(height_ft * 3.28),
    select: u.name
end

为什么我在此 Ecto 查询中收到未绑定的变量消息？

Why Am I Getting An Unbound Variable Message On This Ecto Query?

ecto

phoenix

elixir