JSON Functions¶

json_extract_path_text(json text, json_path text)¶

Extracts JSON string from a JSON string based on json path specified and returns JSON string pointed to by JSONPath. Returns null if either argument is null.

Parameters:	json – JSON string json_path – JSONpath
Return type:	text
Example:

select json_extract_path_text('{"test" : {"key" : "tajo"}}','$.test.key');
> tajo

json_array_get(json_array text, index int4)¶

Returns the element at the specified index into the JSON array. This function returns an element indexed from the end of an array with a negative index, and null if the element at the specified index doesn’t exist.

Parameters:	json_array – String of a JSON array index – index
Return type:	text
Example:

select json_array_get('[100, 200, 300]', 0);
> 100

select json_array_get('[100, 200, 300]', -2);
> 200

json_array_contains(json_array text, value any)¶

Determine if the given value exists in the JSON array.

Parameters:	json_array – String of a JSON array value – value of any type
Return type:	text
Example:

select json_array_contains('[100, 200, 300]', 100);
> t

json_array_length(json_array text)¶

Returns the length of json array.

Parameters:	json_array – String of a JSON array
Return type:	int8
Example:

select json_array_length('[100, 200, 300]');
> 3