MySQL JSON Functions (original) (raw)

Last Updated : 05 Aug, 2024

**JSON functions in **MySQL allow working with **JSON data in the database and retrieve JSON data from it. These functions help in storing and accessing JSON data efficiently and such data is widely used in web applications as it is **flexible and easy to use.

In this article, We will learn about the **MySQL JSON Functions by understanding various functions in detail along with the examples and so on.

What are MySQL JSON Functions?

• **MySQL **JSON functions are procedures that are innately integrated in MySQL to offer the users the ability to create, manage, and manipulate**JSON documents.
• These functions are needed to deal with **JSON data stored in the MySQL tables and allow organizing the work with complex data.

Syntax

Here is the basic syntax for some common JSON functions:

**Creating JSON Data:

SELECT JSON_OBJECT('key1', 'value1', 'key2', 'value2');

**Extracting JSON Values:

SELECT JSON_EXTRACT(json_doc, path);

**Modifying JSON Data:

SELECT JSON_SET(json_doc, path, value);

Why Use JSON in MySQL?

Using JSON in MySQL offers several advantages:

1. Flexibility

• **JSON also has capability to store and manage the structured data with hierarchal structure. This in turn allows one to place objects and arrays contained in a single **JSON document.
• It simplifies the representation of relationships between the data components when designing their structure.

2. Interoperability

• Their main advantages are that JSON is accepted in most cases as a data format, is used without reheating in different platforms and languages.
• Because of its light weight and text format, it is very easy to understand and create; thus it flows well and interoperates and exchanges data between different systems, applications and programming languages.

3. Efficiency

• JSON functions help in simplifying the task of using JSON data within the database by loading/sorting the data at the time of its use.
• MySQL’s native support of **JSON operations also implies that there is no need for JSON to be parsed and further transformed before the command can work, which makes query responses faster and requires less computation time.

4. Scalability

• This flexibility makes it easier to add new fields and structures to JSON since adding new keys will not affect the current software database structures.
• When the application changes, however, for example perhaps weekly, this flexibility is useful in the database as it is able to adapt and expand as necessary without too much alteration.

5. Ease of Use

• Yet, JSON is quite simple and easily readable by developers due to being an extension of the JavaScript scripting language.
• Because of its easily understandable structure, data can be easily consigned, checked for mistakes and modified which overall saves development time.

6. Compatibility with NoSQL Features

• MySQL provides support for JSON in terms of functions, which makes it a middle ground between **Relational and **Non-relational/**NoSQL **databases.
• It means developers are facilitated with the benefits of both paradigms, the structured query to interact with data and the flexible NoSQL background to store data.

Examples of MySQL JSON Functions

Example 1: Creating JSON Data

Let's create a JSON object using JSON_OBJECT.

SELECT JSON_OBJECT('name', 'Alice', 'age', 25, 'city', 'Wonderland');

**Output:

{

"name": "Alice",

"age": 25,

"city": "Wonderland"

}

Example 2: Extracting JSON Values

Let's extract a value from a JSON document using JSON_EXTRACT.

SELECT JSON_EXTRACT('{"name": "Alice", "age": 25, "city": "Wonderland"}', '$.age');

**Output:

25

**Explanation: This query extracts the value of the age key from the given JSON document.

Example 3: Modifying JSON Data

Let's modify a JSON document using JSON_SET.

SELECT JSON_SET('{"name": "Alice", "age": 25, "city": "Wonderland"}', '$.age', 26);

**Output:

{

"name": "Alice",

"age": 26,

"city": "Wonderland"

}

**Explanation: This query modifies the value of the age key in the JSON document from 25 to 26.

MySQL JSON Functions Overview

1. JSON_OBJECT

**JSON_OBJECT is the other function which is used to built the JSON object from keys and values in a set. As also mentioned above, this function is especially essential when it comes to the formation of JSON data directly in the SQL statement.

2. JSON_ARRAY

**JSON_ARRAY constructs a JSON array depending on the particular specified values on a list of values. These can used to represent ordered collections of elements.

**Example:

SELECT JSON_ARRAY('Alice', 25, 'Wonderland');

**Output:

["Alice", 25, "Wonderland"]

3. JSON_MERGE

The JSON_MERGE function combines two or more JSON documents into one. This is useful for aggregating data from multiple JSON objects.

**Example:

SELECT JSON_MERGE('{"name": "Alice"}', '{"age": 25}');

**Output:

{"name": "Alice", "age": 25}

4. JSON_REMOVE

The **JSON_REMOVE function deletes a specified key or path from a JSON document.

**Example:

SELECT JSON_REMOVE('{"name": "Alice", "age": 25}', '$.age');

**Output:

{"name": "Alice"}

5. JSON_ARRAY_APPEND

The JSON_ARRAY_APPEND function adds a value to the end of a JSON array.

**Example:

SELECT JSON_ARRAY_APPEND('["Alice", 25]', '$', 'Wonderland');

**Output:

["Alice", 25, "Wonderland"]

6. JSON_SEARCH

The JSON_SEARCH function searches for a value within a JSON document and returns the path to the matching value.

**Example:

SELECT JSON_SEARCH('{"name": "Alice", "city": "Wonderland"}', 'one', 'Wonderland');

**Output:

"$.city"

Conclusion

Overall, **MySQL JSON functions that are available help when one wants to use **JSON within the **MySQL database. These functions are specifically designed to create, extract and modify **JSON documents which simplifies the data structure processes. When properly utilized, these functions allow the improvement of configurability.