How to restore MySQL database using Python

Question

I have a sql file generated during database backup process and I want to load all database content from that sql file to a different MySQL database (secondary database).

I have created a python function to load the whole database in that sql file but when I execute the function, I get an error

'str' object is not callable

Below is python script

def load_database_dump_to_secondary_mysql(file_path='db_backup_file.sql'):
        query = f'source {file_path}'
        try:
            connection = mysql_hook.get_conn() # connection to secondary db
            cursor = connection.cursor(query)
            print('LOAD TO MYSQL COMPLETE')
        except Exception as xerror:
            print("LOAD ERROR: ", xerror)

NB: mysql_hook is an airflow connector that contains MySQL DB connection info such as Host, user/passwd, Database name. Also, I don't have connection to the primary database, I'm only receiving sql dump file.

What I'm I missing?

Answer 1

source is a client builtin command: https://dev.mysql.com/doc/refman/8.0/en/mysql-commands.html

It's not an SQL query that MySQL's SQL parser understands.

So you can't execute source using cursor.execute() , because that goes directly to the dynamic SQL interface.

You must run it using the MySQL command-line client as a subprocess:

subprocess.run(['mysql', '-e', f'source {file_path}'])

You might need other options to the mysql client, such as user, password, host, etc.

Answer 2

try this

import mysql.connector as m

# database which you want to backup
db = 'geeksforgeeks'

connection = m.connect(host='localhost', user='root',
                    password='123', database=db)
cursor = connection.cursor()

# Getting all the table names
cursor.execute('SHOW TABLES;')
table_names = []
for record in cursor.fetchall():
    table_names.append(record[0])

backup_dbname = db + '_backup'
try:
    cursor.execute(f'CREATE DATABASE {backup_dbname}')
except:
    pass

cursor.execute(f'USE {backup_dbname}')

for table_name in table_names:
    cursor.execute(
        f'CREATE TABLE {table_name} SELECT * FROM {db}.{table_name}')