How to convert MySQL query result to JSON in Python

In this article, you will learn a simple process to convert MySQL query results to JSON using the Python programming.

JSON (JavaScript Object Notation) is a lightweight, open standard file format. It is easy for humans to read and write. It is easy to read and write for humans. It is used primarily to transmit data between a web application and a server. JSON is popular among developers for data serialization. It is so popular that every modern programming language has methods to generate and parse JSON formatted data.

Install MySQL Connector

A connector is a bridge when we have to connect a database with a programming language. It provides access to a database driver to the required language. Python MySQL installer available for different operating systems. You can download the MSI version from here-

The installer requires 'python.exe' in your system PATH; otherwise, it will fail to install. So make sure to add Python to your system environment.

You can also install MySQL Connector using the pip command.

pip install mysql-connector

Python connecting to MySQL

First, we need to import the MySQL connector into the Python file to connect to the database. Then, use the connect() constructor to create a connection to the MySQL server. Make sure to replace the 'user', 'password', 'host', and 'database' with your database credentials.

import mysql.connector

conn = mysql.connector.connect(user='root', password='',
                              host='localhost',database='company')

if conn:
    print ("Connected Successfully")
else:
    print ("Connection Not Established")

Python MySQL Select Table

Here is the MySQL select statement to fetch data from the 'employee' table.

mydict = create_dict()
select_employee = """SELECT * FROM employee"""
cursor = conn.cursor()
cursor.execute(select_employee)
result = cursor.fetchall()

for row in result:
    mydict.add(row[0],({"name":row[1],"email":row[2],"phone":row[3]}))

In the above code, first we have instantiated the create_dict class and called the add() method to store the fetched data in a key-value pair. The class is defined as follows-

class create_dict(dict): 
  
    # __init__ function 
    def __init__(self): 
        self = dict() 
          
    # Function to add key:value 
    def add(self, key, value): 
        self[key] = value

Import JSON Module

import JSON

The JSON module provides the dumps() method for writing data to files. This method takes a data object to be serialized, and the indent attribute specifies the indentation size for nested structures. The sort_keys attribute is a boolean value. If it is TRUE, then the output of dictionaries will be sorted by key.

stud_json = json.dumps(mydict, indent=2, sort_keys=True)

print(stud_json) 

Complete Code: Convert MySQL query result to JSON

Here, we have merged the above code that we explained in chunks to convert the MySQL query results to JSON using the Python programming language.

import mysql.connector
import json

conn = mysql.connector.connect(user='root', password='',
                              host='localhost',database='company')

if conn:
    print ("Connected Successfully")
else:
    print ("Connection Not Established")

class create_dict(dict): 
  
    # __init__ function 
    def __init__(self): 
        self = dict() 
          
    # Function to add key:value 
    def add(self, key, value): 
        self[key] = value

mydict = create_dict()
select_employee = """SELECT * FROM employee"""
cursor = conn.cursor()
cursor.execute(select_employee)
result = cursor.fetchall()

for row in result:
    mydict.add(row[0],({"name":row[1],"email":row[2],"phone":row[3]}))

stud_json = json.dumps(mydict, indent=2, sort_keys=True)

print(stud_json)

The above code returns output in JSON format as follows-

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