我有一个从数据库中选择唯一商店及其产品的功能，但结果会返回f1和f2等键。我可以指定要返回的密钥并使它们更有意义吗？
调用数据库代码的代码：
unique_shops = create_unique_shop_query_no_keyword(categories, shop_ids) |> Api.Repo.all
IO.inspect(unique_shops, label: "unique shops!")
数据库代码：
def create_unique_shop_query_no_keyword(categories, shop_ids) do
products_shops_categories = from p in Product,
join: ps in ProductShop, on: p.id == ps.p_id,
join: s in Shop, on: s.id == ps.s_id,
join: pc in ProductCategory, on: p.id == pc.p_id,
join: c in Subcategory, on: c.id == pc.c_id,
distinct: s.id,
where: c.id in ^categories,
where: s.id in ^shop_ids,
group_by: [s.id, s.name],
select: %{products: fragment(
"json_agg( DISTINCT (?, ?, ?, ?, ?, ?, ?, ?, ?)) AS products",
p.id,
p.name,
p.brand,
p.description,
p.image,
p.rating,
p.number_of_votes,
ps.not_in_shop_count,
ps.price),
shop: fragment(
"json_agg( DISTINCT (?, ?, ST_X(?), ST_Y(?))) AS shop",
s.id,
s.name,
s.point,
s.point
)
}
end
这是目前返回的内容：
unique shops!: [
%{
products: [
%{
"f1" => 96,
"f2" => "reverb",
"f3" => "verve",
"f4" => "we’ve ever revere",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 34
},
%{
"f1" => 97,
"f2" => "clear we",
"f3" => "wfwegwaeg",
"f4" => "vervaerververv",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 444
},
%{
"f1" => 98,
"f2" => "sdvsd",
"f3" => "few",
"f4" => "svsdvsdvsdvsdv",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 3
},
%{
"f1" => 99,
"f2" => "sdvsdd",
"f3" => "fewer",
"f4" => "svsdvsdvsdvsdv",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 3
},
%{
"f1" => 100,
"f2" => "badd",
"f3" => "vegd",
"f4" => "sdvsdvsdvsd",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 33
},
%{
"f1" => 101,
"f2" => "veer was",
"f3" => "be",
"f4" => "rverververvrqv",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 444
},
%{
"f1" => 102,
"f2" => "erverve",
"f3" => "every",
"f4" => "rverververveqrv",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 44
},
%{
"f1" => 104,
"f2" => "eve",
"f3" => "g",
"f4" => "fdvrervqergregeqrg",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => nil
},
%{
"f1" => 105,
"f2" => "v",
"f3" => "be",
"f4" => "verververbebrerbe",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => nil
},
%{
"f1" => 106,
"f2" => "B.B.",
"f3" => "cweveve",
"f4" => "ewvrvreqveqrvervqerv",
"f5" => "https://vepo-images.s3.amazonaws.com/product-images%2FIMG_0001.JPG",
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 3
},
%{
"f1" => 107,
"f2" => "be",
"f3" => "vrvvrv",
"f4" => "vrvrvrvrvrvrv",
"f5" => "https://vepo-images.s3.amazonaws.com/product-images%2FIMG_0005.JPG",
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 4
},
%{
"f1" => 108,
"f2" => "besvwv",
"f3" => "vrvvrv",
"f4" => "vrvrvrvrvrvrv",
"f5" => "https://vepo-images.s3.amazonaws.com/product-images%2FIMG_0005.JPG",
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 4
}
],
shop: [
%{
"f1" => 30,
"f2" => "Ryoko's Japanese Restaurant & Bar",
"f3" => -122.4119976,
"f4" => 37.788211
}
]
},
%{
products: [
%{
"f1" => 103,
"f2" => "vearvr",
"f3" => "fewer",
"f4" => "varevaeaver",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => nil
},
%{
"f1" => 109,
"f2" => "we’vewdvcwce",
"f3" => "few saves",
"f4" => "cwecwecwecwecwecwevw",
"f5" => nil,
"f6" => nil,
"f7" => nil,
"f8" => 0,
"f9" => 33233
}
],
shop: [
%{
"f1" => 53,
"f2" => "Red Dog Restaurant & Bar",
"f3" => -122.395457,
"f4" => 37.784809
}
]
}
]
如何指定从数据库返回的值的键名？
我尝试了一些事情，例如：
shop: fragment(
"json_agg( DISTINCT json_build_object(?, 'id', ?,'so', ST_X(?), 'ff',ST_Y(?),'dd')) AS shop",
s.id,
s.name,
s.point,
s.point
)
}
来自this SO answer以及来自here的一些内容但是知道如何在片段内写入它有点困难。
我的postgres版本是10.4