How to Filter Json Column In Postgresql in 2024?

To filter a JSON column in PostgreSQL, you can use the -> or ->> operators to extract a specific value from a JSON object, or the #> or #>> operators to extract a JSON sub-object. You can also use the ->> operator along with the LIKE or ILIKE operators to search for a specific string within the JSON object. Additionally, you can use the WHERE clause in a query to filter rows based on the values contained within a JSON column.

How to filter JSON column by type in PostgreSQL?

To filter a JSON column by type in PostgreSQL, you can use the json_typeof function to determine the data type of the JSON value and then apply a filter based on the type. Here's an example of how you can filter a JSON column named data by the type of its values:

-- Filter JSON column by type
SELECT *
FROM my_table
WHERE json_typeof(data) = 'object'; -- Filter by object type

-- Other types: 'array', 'string', 'number', 'boolean', 'null'

In this example, we are filtering the data column in the my_table table to only return rows where the JSON value is of type object. You can change the filter condition to match other data types such as array, string, number, boolean, or null as needed.

Remember that the json_typeof function returns the data type of a JSON value as a text string, which can be compared against the desired type to filter the results.

What is the difference between JSON_CONTAINS and JSON_EXTRACT functions in PostgreSQL?

In PostgreSQL, JSON_CONTAINS is a function that checks if a specified JSON value is contained within another JSON value. It returns true if the specified value is found, otherwise it returns false.

On the other hand, JSON_EXTRACT is a function that extracts a specified JSON value from a JSON document. It allows you to extract a specific value from a JSON document based on a provided path.

In summary, JSON_CONTAINS is used to check if a value is present in a JSON document, while JSON_EXTRACT is used to extract a specific value from a JSON document.

What is the storage format of a JSON column in PostgreSQL?

In PostgreSQL, the storage format of a JSON column is as a text string. The JSON data is stored as plain text in the table, and PostgreSQL provides functions to parse and manipulate the JSON data within queries. PostgreSQL does not have a dedicated JSON data type like some other databases, instead treating JSON data as text that can be indexed and queried using special operators and functions.

How to filter JSON column by array in PostgreSQL?

To filter a JSON column by an array in PostgreSQL, you can use the JSONB_ARRAY_ELEMENTS function to extract the elements of the JSON array and then use the IN operator to filter the results.

Here is an example query that filters a JSON column named data by an array of values:

1
2
3

SELECT *
FROM your_table
WHERE JSONB_ARRAY_ELEMENTS(data) IN ('value1', 'value2', 'value3');

In this query, your_table is the name of the table with the JSON column, data is the name of the JSON column you want to filter, and value1, value2, and value3 are the array values you want to filter by.

This query will return all rows where the JSON column data contains any of the values in the array ('value1', 'value2', 'value3').

How to use JSON_VALUE function to filter JSON column in PostgreSQL?

To use the JSON_VALUE function to filter a JSON column in PostgreSQL, you first need to make sure you have the jsquery extension installed. This extension provides support for querying and manipulating JSON data in PostgreSQL.

Here is an example of how you can use the JSON_VALUE function to filter a JSON column in PostgreSQL:

Install jsquery extension if you don't have it already:

1	CREATE EXTENSION jsquery;

Create a table with a JSON column:

CREATE TABLE products (
    id SERIAL PRIMARY KEY,
    details JSON
);

INSERT INTO products (details)
VALUES
    ('{"name": "Product A", "price": 50}'),
    ('{"name": "Product B", "price": 70}'),
    ('{"name": "Product C", "price": 100}');

Filter the JSON column using the JSON_VALUE function:

1
2
3

SELECT *
FROM products
WHERE JSON_VALUE(details, '$.price') > 60;

In this example, we are using the JSON_VALUE function to extract the value of the "price" key in the JSON column and then filtering the rows where the price is greater than 60.

You can also use JSON_VALUE function to filter based on other keys or conditions within the JSON data.

How to filter JSON column by complex criteria in PostgreSQL?

To filter a JSON column by complex criteria in PostgreSQL, you can use the jsonb data type and the ->> operator to access specific keys within the JSON document. Here is an example of how you can filter a JSON column based on a complex criteria:

Assuming we have a table called products with a jsonb column called attributes that stores various attributes of each product, let's say we want to filter products based on the following criteria:

The product must have a price greater than 50
The product must have a "color" attribute with the value "blue"

You can achieve this by using the following query:

SELECT *
FROM products
WHERE attributes->>'price'::numeric > 50
AND attributes @> '{"color": "blue"}';

In this query, the ->> operator is used to extract the price attribute as a numeric value, and the @> operator is used to check if the JSON document contains the specified key-value pair for the color attribute.

You can modify the query to suit your specific criteria by changing the key names and values to match the attributes you want to filter on.

coding.ignorelist.com

How to Filter Json Column In Postgresql?