group (Aggregate Function)
This function aggregates the JSON elements and returns a JSON object by adding enclosing.element if it is provided. If enclosing.element is not provided it aggregate the JSON elements returns a JSON array.
Syntax
<OBJECT> json:group(<STRING|OBJECT> json)
<OBJECT> json:group(<STRING|OBJECT> json, <BOOL> distinct)
<OBJECT> json:group(<STRING|OBJECT> json, <STRING> enclosing.element)
<OBJECT> json:group(<STRING|OBJECT> json, <STRING> enclosing.element, <BOOL> distinct)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| json | The JSON element that needs to be aggregated. | STRING OBJECT | No | Yes | |
| enclosing.element | The JSON element used to enclose the aggregated JSON elements. | EMPTY_STRING | STRING | Yes | Yes |
| distinct | This is used to only have distinct JSON elements in the concatenated JSON object/array that is returned. | false | BOOL | Yes | Yes |
Example 1
select json:group("json") as groupedJSONArray
from InputStream WINDOW SLIDING_LENGTH(5)
input OutputStream;
When we input events having values for the json as
{"date":"2013-11-19","time":"10:30"} and
{"date":"2013-11-19","time":"12:20"}, it returns
[{"date":"2013-11-19","time":"10:30"}{"date":"2013-11-19","time":"12:20"}]
to the OutputStream.
Example 2
select json:group("json", true) as groupedJSONArray
from InputStream WINDOW SLIDING_LENGTH(5)
input OutputStream;
When we input events having values for the json as
{"date":"2013-11-19","time":"10:30"} and
{"date":"2013-11-19","time":"10:30"}, it returns
[{"date":"2013-11-19","time":"10:30"}] to the OutputStream.
Example 3
select json:group("json", "result") as groupedJSONArray
from InputStream WINDOW SLIDING_LENGTH(5)
input OutputStream;
When we input events having values for the json as
{"date":"2013-11-19","time":"10:30"} and
{"date":"2013-11-19","time":"12:20"}, it returns
{"result":[{"date":"2013-11-19","time":"10:30"},{"date":"2013-11-19","time":"12:20"}}
to the OutputStream.
Example 4
select json:group("json", "result", true) as groupedJSONArray
from InputStream WINDOW SLIDING_LENGTH(5)
input OutputStream;
When we input events having values for the json as {"date":"2013-11-19","time":"10:30"} and {"date":"2013-11-19","time":"10:30"}, it returns {"result":[{"date":"2013-11-19","time":"10:30"}]} to the OutputStream.