import json
import mysql.connector

mydb = mysql.connector.connect(host=x,user=x,password=x,database=x)
cursor = mydb.cursor()

json_data = json.loads(file)

for item in json_data['data']:
   cursor.execute("INSERT INTO input_1 (a,b,c,d) VALUES (%s,%s,%s,%s)", (item['a'],item['b'],item['c'],item['d']))

import json
import mysql.connector

mydb = mysql.connector.connect(host=x,user=x,password=x,database=x)
cursor = mydb.cursor()

json_data = json.loads(file)

for item in json_data['data']:
   cursor.execute("INSERT INTO input_1 (a,b,c,d) VALUES (%s,%s,%s,%s) ON DUPLICATE KEY UPDATE VALUES a=%s,b=%s,c=%s", (item['a'],item['b'],item['c'],item['d']))