To access data from Opsgenie, you will need to use their REST API. Start by creating an API key in Opsgenie. Go to the Opsgenie console, navigate to "Settings" > "API Key Management," and create a new API key with read access to the data you wish to export.

Ensure you have Python installed on your system as it will be used to script the data transfer. Additionally, install the `requests` library to interact with the Opsgenie API and `mysql-connector-python` to insert data into MySQL. You can install these using pip:
```bash
pip install requests mysql-connector-python
```

Write a Python script to fetch data from Opsgenie using the API. Utilize the `requests` library to make GET requests to the relevant Opsgenie endpoints, passing the API key for authentication. Here’s a basic example:
```python
import requests

def fetch_opsgenie_data():
url = "https://api.opsgenie.com/v2/alerts"
headers = {
"Authorization": "GenieKey YOUR_API_KEY"
}
response = requests.get(url, headers=headers)
if response.status_code == 200:
return response.json()
else:
raise Exception("Failed to fetch data: " + response.text)

data = fetch_opsgenie_data()
```

Parse the JSON response from Opsgenie and prepare it for insertion into the MySQL database. This may involve extracting specific fields and formatting them as needed. Ensure you handle any nested JSON structures appropriately.

Ensure that you have a MySQL server running and create a database and table where the data will be stored. Define the schema based on the data structure obtained from Opsgenie. Use the MySQL command line or a GUI tool to execute SQL commands to create the necessary tables.

Using the `mysql-connector-python` library, connect to your MySQL database and insert the data. Below is a sample Python function to insert data into MySQL:
```python
import mysql.connector

def insert_data_to_mysql(data):
connection = mysql.connector.connect(
host="localhost",
user="your_username",
password="your_password",
database="your_database"
)
cursor = connection.cursor()

insert_query = "INSERT INTO your_table (field1, field2) VALUES (%s, %s)"
for item in data['alerts']: # Assuming 'alerts' is the key containing the data
cursor.execute(insert_query, (item['field1'], item['field2']))

connection.commit()
cursor.close()
connection.close()

insert_data_to_mysql(data)
```

To ensure data is regularly updated, automate this script using a task scheduler like cron (Linux) or Task Scheduler (Windows). Schedule the script to run at intervals that suit your data update needs, ensuring that the API usage limits and your server’s capacity are considered.

By following these steps, you'll be able to transfer data from Opsgenie to a MySQL database manually and programmatically, without relying on third-party connectors or integrations.