JSON有查询语言吗?

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

我使用SQLite: https://sqlite.org/json1.html

这很好，因为你可以使用实际的SQL语言，SQLite非常快。

首先我创建一个临时表:

create temp table data as select value from json_each(readfile('data.json'))

然后使用SQLite JSON函数:

select value->'$.foo' foo, count(value->'$.bar') nbar from data group by foo

2022-10-14 08:55:19

其他回答

更新:XQuery 3.1可以查询XML或JSON—或者同时查询两者。XPath 3.1也可以。

这个名单还在增加:

JSONiq(基于XQuery) UNQL(类似SQL) JaQL(功能) JsonPath(于xpath) Json查询(类似于xpath) GraphQL(基于模板，类型化)

2011-10-18 18:42:44

如果你使用python, MongoDB有迷你开源版本， MontyDB https://github.com/davidlatwe/montydb 它在github上有500多颗星，并且得到了JetBrains的支持。

from montydb.utils import MontyList
response = [
    {'namespace': 'dash_mantine_components',
     'props': {'checked': True,
               'id': {'index': 0, 'type': 'checkbox'},
               'label': 'My first to do'},
     'type': 'Checkbox'},
    {'namespace': 'dash_mantine_components',
     'props': {'checked': True,
               'id': {'index': 1, 'type': 'checkbox'},
               'label': 'My Another to do'},
     'type': 'Input'}, 
    {'namespace': 'dash_mantine_components',
     'props': {'checked': False,
               'id': {'index': 2, 'type': 'checkbox'},
               'label': 'My next level to do'},
     'type': 'Div'}, 
]

cli = MontyList(response)
cli.find({'props.checked': True},{'type':1})

输出:

MontyList([{'type': 'Checkbox'}, {'type': 'Input'}])

与其他jsonquery选项相比，我更喜欢这个库，因为这个库提供了与MongoDB相同的感觉。

2022-08-31 19:51:31

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'

2012-12-03 21:42:54

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));

2020-11-21 16:47:02

PythonQL提供了一种嵌入式语法，IMHO是对SQL的改进，主要是因为group、window、where、let等可以自由混合。

$ cat x.py
#coding: pythonql
data = [{"x": 2, "y": 0}, {"x": 3, "y": 1}, {"x": 4, "y": 1}]
q = [x match {'x': as x, 'y': as y} in data where y > 0]
print(sum(q))
print(list(q))

q = [x match {'x': as x, 'y': as y} as d in data where d['y'] > 0]
print(sum(q))

这段代码显示了您的问题的两个不同答案，这取决于您需要处理整个结构或仅处理值。执行会给你预期的结果。

$ python x.py
7
[3, 4]
7

2020-03-07 18:37:08

JSON有查询语言吗?

推荐文章

最新文章

标签