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我想在未預載的情況下在預載映射中添加變更集，但無法弄清楚如何插入變更集;任何想法？添加變更集以預加載
我的變更被打印出來，但在IO.inspect（項目）未見其蹤影......
def select(conn, %{"list_id" => list_id}) do
list = Repo.get!(List, list_id)
list_id = list.id
query = from l in Learnit.Itemlist, where: l.list_id == ^list_id # Filter on the list's ID
items =
Item
|> Repo.all()
|> Repo.preload(itemlists: query)
|> Enum.map(&add_changeset(&1, list_id)) # Loop through the items to add changesets if there is no itemlist yet
render(conn, "select.html", items: items, list: list)
end
defp add_changeset(item, list_id) do
case Enum.count(item.itemlists) do
0 -> # There is no itemlists yet : we create the changeset
changeset = Itemlist.changeset(%Itemlist{}, %{item_id: item.id, list_id: list_id})
IO.inspect(changeset)
Map.put(item, :changeset, changeset)
IO.inspect(item)
end
end