> This page location: JSON Functions > jsonb_path_query_first > Full Neon documentation index: https://neon.com/docs/llms.txt # PostgreSQL jsonb_path_query_first() Function **Summary**: in this tutorial, you will learn how to use the PostgreSQL `jsonb_path_query_first()` function to extract the first JSON value that matches a JSON path expression from a JSON document. ## Introduction to the PostgreSQL jsonb_path_query_first() function The `jsonb_path_query_first()` function allows you to query data from a [JSONB document](../postgresql-tutorial/postgresql-json) based on a [JSON path](https://neon.com/postgresql/postgresql-json-functions/postgresql-json-path) expression and return the first match. Here's the basic syntax of the `jsonb_path_query_first()` function: ```sql jsonb_path_query_first(jsonb_data, json_path) ``` In this syntax: - First, specify a JSONB data from which you want to query data. - Second, provide a JSON path to match elements in the JSONB data. If the `jsonb_path_query_first()` function doesn't find any match, it returns `NULL`. ## PostgreSQL jsonb_path_query_first() function examples Let's explore some examples of using the `jsonb_path_query_first()` function. ### 1) Basic jsonb_path_query_first() function example The following example uses the `jsonb_path_query_first()` function to get the first pet of a person: ```sql SELECT jsonb_path_query_first( '{"name": "Alice", "pets": ["Lucy","Bella"]}', '$.pets[*]' ) AS first_pet_name; ``` Output: ```text first_pet_name ---------------- "Lucy" (1 row) ``` ### 2) Using the jsonb_path_query_first() function with table data First, [create a new table](../postgresql-tutorial/postgresql-create-table) called `person`: ```sql CREATE TABLE person ( id SERIAL PRIMARY KEY, data JSONB ); ``` In the `person` table, the `data` column has the type of JSONB that stores employee information including name, age, and pets. Second, [insert data](../postgresql-tutorial/postgresql-insert-multiple-rows) into the `person` table: ```sql INSERT INTO person (data) VALUES ('{"name": "Alice", "age": 30, "pets": [{"type": "cat", "name": "Fluffy"}, {"type": "dog", "name": "Buddy"}]}'), ('{"name": "Bob", "age": 35, "pets": [{"type": "dog", "name": "Max"}]}'), ('{"name": "Charlie", "age": 40, "pets": [{"type": "rabbit", "name": "Snowball"}]}') RETURNING *; ``` Third, retrieve the first pet name using the `jsonb_path_query_first()` function: ```sql SELECT jsonb_path_query_first(data, '$.pets[*].name') AS first_pet_name FROM person; ``` Output: ```text first_pet_name ---------------- "Fluffy" "Max" "Snowball" (3 rows) ``` ### 3) Handling missing paths The following example attempts to find an element whose path does not exist: ```sql SELECT jsonb_path_query_first(data, '$.email') FROM person; ``` Output: ```text jsonb_path_query_first ------------------------ null null null (3 rows) ``` In this case, the person object doesn't have an `email` key, therefore the result is `NULL`. ## Summary - Use the `jsonb_path_query_first()` function to extract the first JSON value that matches a JSON path expression from a JSON document. --- ## Related docs (JSON Functions) - [Extracting JSON Data](https://neon.com/postgresql/postgresql-json-functions/postgresql-json-extract) - [JSONB Operators](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb-operators) - [jsonb_agg](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_agg) - [jsonb_array_elements](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_array_elements) - [jsonb_array_elements_text](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_array_elements_text) - [jsonb_array_length](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_array_length) - [jsonb_build_array](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_build_array) - [jsonb_build_object](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_build_object) - [jsonb_each](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_each) - [jsonb_each_text](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_each_text) - [jsonb_extract_path](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_extract_path) - [jsonb_extract_path_text](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_extract_path_text) - [jsonb_insert](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_insert) - [jsonb_object](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_object) - [jsonb_object_agg](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_object_agg) - [jsonb_object_keys](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_object_keys) - [JSON Path](https://neon.com/postgresql/postgresql-json-functions/postgresql-json-path) - [jsonb_path_exists](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_path_exists) - [jsonb_path_query](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_path_query) - [jsonb_path_query_array](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_path_query_array) - [jsonb_pretty](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_pretty) - [jsonb_set](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_set) - [jsonb_strip_nulls](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_strip_nulls) - [jsonb_to_record](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_to_record) - [jsonb_populate_record](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_populate_record) - [jsonb_populate_recordset](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_populate_recordset) - [jsonb_typeof](https://neon.com/postgresql/postgresql-json-functions/postgresql-jsonb_typeof) - [row_to_json](https://neon.com/postgresql/postgresql-json-functions/postgresql-row_to_json) - [to_jsonb](https://neon.com/postgresql/postgresql-json-functions/postgresql-to_jsonb)