Elixir Ecto-根据共享字段值将项目编译为单个项目

Question

如果我有：

[
%{group: "123", name: "John"},
%{group: "123", name: "Jane"},
%{group: "123", name: "James"},
]

我如何将其转换为：

%{
group: "123", 
members: [%{name: "John"}, %{name: "Jane"}, %{name: "James"}]
}

我尝试：

from m in Module.Member,
group_by: m.group, 
... #with a few different queries...

但刚刚了解到group_by不是这样工作的

Answer 1

根据您想要的通用性级别，这可能就足够了：

data = [
%{group: "123", name: "John"},
%{group: "123", name: "Jane"},
%{group: "123", name: "James"},
]
members = Enum.map(data, fn p -> %{name: p.name} end)
result = %{group: Enum.at(data, 0).group, members: members}

这不会处理数据中不同组号的情况。