Join on preloads to avoid N+1 queries

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href 2019-01-26 15:55:53 +01:00
parent 6383fa3a5d
commit 8018ae7ae5
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2 changed files with 10 additions and 3 deletions

View File

@ -35,7 +35,8 @@ def for_user(user, opts \\ %{}) do
n in Notification, n in Notification,
where: n.user_id == ^user.id, where: n.user_id == ^user.id,
order_by: [desc: n.id], order_by: [desc: n.id],
preload: [:activity], join: activity in assoc(n, :activity),
preload: [activity: activity],
limit: 20 limit: 20
) )
@ -66,7 +67,8 @@ def get(%{id: user_id} = _user, id) do
from( from(
n in Notification, n in Notification,
where: n.id == ^id, where: n.id == ^id,
preload: [:activity] join: activity in assoc(n, :activity),
preload: [activity: activity]
) )
notification = Repo.one(query) notification = Repo.one(query)

View File

@ -33,7 +33,12 @@ def call(conn, _) do
# #
@spec fetch_user_and_token(String.t()) :: {:ok, User.t(), Token.t()} | nil @spec fetch_user_and_token(String.t()) :: {:ok, User.t(), Token.t()} | nil
defp fetch_user_and_token(token) do defp fetch_user_and_token(token) do
query = from(q in Token, where: q.token == ^token, preload: [:user]) query =
from(t in Token,
where: t.token == ^token,
join: user in assoc(t, :user),
preload: [user: user]
)
with %Token{user: %{info: %{deactivated: false} = _} = user} = token_record <- Repo.one(query) do with %Token{user: %{info: %{deactivated: false} = _} = user} = token_record <- Repo.one(query) do
{:ok, user, token_record} {:ok, user, token_record}