PostgreSQL jsonb_path_exists() Function

The PostgreSQL jsonb_path_exists() function checks whether a specified path returns a value in a given JSON.

jsonb_path_exists() Syntax

This is the syntax of the PostgreSQL jsonb_path_exists() function:

jsonb_path_exists(target JSONB, path JSONPATH [, vars JSONB [, silent BOOLEAN]]) -> BOOLEAN

Parameters

target

Required. The JSONB value to check.

path

Required. The JSON path to check, it is of JSONPATH type .

vars

Optional. The variable values used in the path. It is a JSON object.

silent

Optional. If this parameter is provided and is true, the function suppresses the same errors as the @? and @@ operators.

Return value

The PostgreSQL jsonb_path_exists() function returns a boolean value that is the result of checking whether the specified path returns a value in a JSONB value. t indicates that the specified path has a return value, and f indicates that the specified path has no return value.

If any parameter is NULL, the jsonb_path_exists() function will return NULL.

jsonb_path_exists() Examples

The following example shows how to use the PostgreSQL jsonb_path_exists() function to check if a specified JSON path has a value in a JSON array.

SELECT jsonb_path_exists('[1, 2, 3]', '$[*] ? (@ > 1)');

 jsonb_path_exists
-------------------
 t

Here, we use path $[*] ? (@ > 2) to get items greater than 2 in the JSON array [1, 2, 3]. We can use the jsonb_path_query_array() function to verify that if the above results is correct:

SELECT jsonb_path_query_array('[1, 2, 3]', '$[*] ? (@ > 1)');

 jsonb_path_query_array
------------------------
 [2, 3]

We can use variables in JSON paths like this:

SELECT jsonb_path_exists(
    '[1, 2, 3, 4]',
    '$[*] ? (@ >= $min && @ <= $max)',
    '{"min": 2, "max": 3}'
);

 jsonb_path_exists
-------------------
 t

Here, we used two variables min and max in the JSON path $[*] ? (@ >= $min && @ <= $max), and we have provided values {"min": 2, "max": 3} ​​for the variables in var, so that the JSON path becomed $[*] ? (@ >= 2 && @ <= 3). That is, the function checked if the array [1, 2, 3, 4] contains values ​​greater than or equal to 2 and less than or equal to 3.