Json Path

JSON-PATH directive uses a DSL for reading json records.

Syntax

json-path <source-column> <destination-column> <expression>

source-columnspecifies the name of the column in the record that should be considered as "root member object" or "$".destination-columnis the name of the output column in the record where the results of expression will be stored.expressionis json path expression, see below for more details.

Usage Notes

The expressions always refer to a Json structure in the same way as XPath expression are used in combination with an XML document.The "root member object" is always referred to as$regardless if it is an object or array.

Expressions can use the dot–notation

$.name.first

or the bracket–notation

$['name']['first']

Operators

Operator	Description
`$`	The root element to query. This starts all path expressions.
`@`	The current node being processed by a filter predicate.
`*`	Wildcard. Available anywhere a name or numeric are required.
`..`	Deep scan. Available anywhere a name is required.
`.<name>`	Dot-notated child
`['<name>' (, '<name>')]`	Bracket-notated child or children
`[<number> (, <number>)]`	Array index or indexes
`[start:end]`	Array slice operator
`[?(<expression>)]`	Filter expression. Expression must evaluate to a boolean value.

Functions

Functions can be invoked at the tail end of a path - the input to a function is the output of the path expression. The function output is dictated by the function itself.

Function	Description	Output
min()	Provides the min value of an array of numbers	Double
max()	Provides the max value of an array of numbers	Double
avg()	Provides the average value of an array of numbers	Double
stddev()	Provides the standard deviation value of an array of numbers	Double
length()	Provides the length of an array	Integer

Filter Operators

Filters are logical expressions used to filter arrays. A typical filter would be[?(@.age > 18)]where@represents the current item being processed. More complex filters can be created with logical operators&&and||. String literals must be enclosed by single or double quotes ([?(@.color == 'blue')]or[?(@.color == "blue")]).

Operator	Description
==	left is equal to right (note that 1 is not equal to '1')
!=	left is not equal to right
<	left is less than right
<=	left is less or equal to right
>	left is greater than right
>=	left is greater than or equal to right
=~	left matches regular expression [?(@.name =~ /foo.*?/i)]
in	left exists in right [?(@.size in ['S', 'M'])]
nin	left does not exists in right
size	size of left (array or string) should match right
empty	left (array or string) should be empty

Example

Given the json

{
    "store": {
        "book": [
            {
                "category": "reference",
                "author": "Nigel Rees",
                "title": "Sayings of the Century",
                "price": 8.95
            },
            {
                "category": "fiction",
                "author": "Evelyn Waugh",
                "title": "Sword of Honour",
                "price": 12.99
            },
            {
                "category": "fiction",
                "author": "Herman Melville",
                "title": "Moby Dick",
                "isbn": "0-553-21311-3",
                "price": 8.99
            },
            {
                "category": "fiction",
                "author": "J. R. R. Tolkien",
                "title": "The Lord of the Rings",
                "isbn": "0-395-19395-8",
                "price": 22.99
            }
        ],
        "bicycle": {
            "color": "red",
            "price": 19.95
        }
    },
    "expensive": 10
}

JsonPath (click link to try)	Result
$.store.book[*].author	The authors of all books
$..author	All authors
$.store.*	All things, both books and bicycles
$.store..price	The price of everything
$..book[2]	The third book
$..book[0,1]	The first two books
$..book[:2]	All books from index 0 (inclusive) until index 2 (exclusive)
$..book[1:2]	All books from index 1 (inclusive) until index 2 (exclusive)
$..book[-2:]	Last two books
$..book[2:]	Book number two from tail
$..book[?(@.isbn)]	All books with an ISBN number
$.store.book[?(@.price < 10)]	All books in store cheaper than 10
[$..book[?(@.price <= $['expensive'])]]([http://jsonpath.herokuapp.com/?path=$..book\[?\(@.price](http://jsonpath.herokuapp.com/?path=$..book[?%[email protected]) <= $['expensive']%29])	All books in store that are not "expensive"
$..book[?(@.author =~ /.*REES/i)]	All books matching regex (ignore case)
$..*	Give me every thing
$..book.length()	The number of books

JSON Path