是否有(大致)SQL或类似xquery的语言来查询JSON?

我正在考虑非常小的数据集,很好地映射到JSON,它将很容易回答查询,如“X的所有值是什么,Y > 3”或做通常的SUM / COUNT类型操作。

作为一个完全虚构的例子,是这样的:

[{"x": 2, "y": 0}}, {"x": 3, "y": 1}, {"x": 4, "y": 1}]

SUM(X) WHERE Y > 0     (would equate to 7)
LIST(X) WHERE Y > 0    (would equate to [3,4])

我认为这将在客户端和服务器端工作,结果将被转换为适当的特定于语言的数据结构(或者可能保留为JSON)

快速搜索一下谷歌,就会发现人们已经考虑过它并实现了一些东西(JAQL),但它似乎还没有一个标准的用法或库集出现。虽然单独实现每个功能都是相当琐碎的,但如果有人已经做对了,我就不想重新发明轮子。

有什么建议吗?

Edit: This may indeed be a bad idea or JSON may be too generic a format for what I'm thinking.. The reason for wanting a query language instead of just doing the summing/etc functions directly as needed is that I hope to build the queries dynamically based on user-input. Kinda like the argument that "we don't need SQL, we can just write the functions we need". Eventually that either gets out of hand or you end up writing your own version of SQL as you push it further and further. (Okay, I know that is a bit of a silly argument, but you get the idea..)


当前回答

下面是一些简单的javascript库,也可以做到这一点:

Dollar Q is a nice lightweight library. It has a familiar feel to the chaining syntax made popular by jQuery and is only 373 SLOC. SpahQL is a fully featured query language with a syntax similar to XPath (Homepage, Github jFunk is an in progress query language, with a syntax similar to CSS/jQuery selectors. It looked promising, but hasn't had any development beyond its in initial commit. (added 2014): the jq command line tool has a neat syntax, but unfortunately it is a c library. Example usage: < package.json jq '.dependencies | to_entries | .[] | select(.value | startswith("git")) | .key'

其他回答

我推荐我正在做的项目jLinq。我在寻求反馈,所以我很有兴趣听听你的想法。

如果让你写查询类似于你会在LINQ…

var results = jLinq.from(records.users)

    //you can join records
    .join(records.locations, "location", "locationId", "id")

    //write queries on the data
    .startsWith("firstname", "j")
    .or("k") //automatically remembers field and command names

    //even query joined items
    .equals("location.state", "TX")

    //and even do custom selections
    .select(function(rec) {
        return {
            fullname : rec.firstname + " " + rec.lastname,
            city : rec.location.city,
            ageInTenYears : (rec.age + 10)
        };
    });

它也是完全可扩展的!

文档仍在编写中,但您仍然可以在线尝试。

只要有可能,我就会将所有查询转移到服务器的后端(SQL DB或其他本地数据库类型)。原因是这样查询会更快更优化。

我知道jSON可以是独立的,对于查询语言可能有+/-,但如果您从后端检索数据到浏览器,我看不出它的优势,因为大多数jSON用例都是这样。在后端进行查询和筛选,以获得所需的尽可能小的数据。

如果出于某种原因,你需要在前端进行查询(主要是在浏览器中),那么我建议只使用数组。过滤器(为什么要发明其他东西?)

也就是说,我认为更有用的是json的转换API…它们更有用,因为一旦你有了数据,你可能想要以多种方式显示它。但是,同样,如果您使用的是server<——>客户端模型,那么您可以在服务器上比在客户端上更容易地完成这些工作。

只值我的两便士!

如果你想使用纯javascript试试这个:

Var对象= {result: {data: {point1: "x", value: 2}, foo: {bar: 7}}}, Path = 'result.data.value', getValue = (o, p) => p.split('.')。Reduce ((r, k) => r[k], o); console.log (getValue(对象,路径));

下面是一些简单的javascript库,也可以做到这一点:

Dollar Q is a nice lightweight library. It has a familiar feel to the chaining syntax made popular by jQuery and is only 373 SLOC. SpahQL is a fully featured query language with a syntax similar to XPath (Homepage, Github jFunk is an in progress query language, with a syntax similar to CSS/jQuery selectors. It looked promising, but hasn't had any development beyond its in initial commit. (added 2014): the jq command line tool has a neat syntax, but unfortunately it is a c library. Example usage: < package.json jq '.dependencies | to_entries | .[] | select(.value | startswith("git")) | .key'

查看https://github.com/niclasko/Cypher.js(注:我是作者)

它是Cypher图形数据库查询语言和图形数据库的零依赖Javascript实现。它运行在浏览器(测试与Firefox, Chrome, IE)。

与问题相关。它可以用来查询JSON端点:

load json from "http://url/endpoint" as l return l limit 10

下面是一个查询复杂JSON文档并对其进行分析的示例:

js JSON查询示例