MySQL JSON type data handling in python

mysql-json-ex.py

import mysql.connector
import json

config = {
    "user":     "",
    "password": "",
    "host":     "localhost",
    "database": "test",
    "use_pure": True,
}

json_data = {
    "Name":         "Harry Potter",
    "Email":        "harry@earth.world",
    "CellPhone":    "xxx0000xxx",
    "Address":      "Earth, Milky Way!!"
}

b_data = json.dumps(json_data)
docID = 1

cnx = mysql.connector.connect(**config)
cursor = cnx.cursor(prepared=True)

# stmt = "UPDATE JSONDoc SET Data = JSON_REPLACE(Data, CONCAT('$', %s), CAST(%s AS JSON)) WHERE DocID=%s"
stmt = "UPDATE JSONDoc SET Data = JSON_REPLACE(Data, CONCAT('$', %s), %s) WHERE DocID=%s"
cursor.execute(stmt, ("", b_data, docID))
cnx.commit()
cursor.close()
cnx.close()

This doesn't work because how exactly is the interpreter going to understand that '{"Foo": "Bar}' is an object and not a primitive string?

Firstly, if you just want to set the Data column's "root" value to be an object, just use SET Data = %s.

If you want the query to allow setting arbitrary path values, don't use JSON_REPLACE, as it can only replace existing paths. Use JSON_SET, and be sure to return a json_document by calling JSON_EXTRACT(json_document,path):

UPDATE JSONDoc SET Data = JSON_SET(Data,CONCAT('$',%s),JSON_EXTRACT(%s,'$')) WHERE DocID = %s

Again, for setting the whole document, you don't need the JSON functions at all.