How to load data from Alpha Vantage to Postgres destination

Begin by creating a free account on the Alpha Vantage website to obtain an API key. This key will allow you to make requests to the Alpha Vantage API for financial data.

To interact with the Alpha Vantage API and PostgreSQL, ensure you have Python installed along with the necessary libraries. Use pip to install the requests library for API calls and psycopg2 for PostgreSQL interaction:
```
pip install requests psycopg2
```

Write a Python script to make a GET request to the Alpha Vantage API endpoint using your API key. Specify the desired function and parameters to retrieve the required data, like time series or stock quotes. Here's a basic example:
```python
import requests

API_KEY = 'your_alpha_vantage_api_key'
url = f'https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=IBM&apikey={API_KEY}'

response = requests.get(url)
data = response.json()
```

Once you have the data in JSON format, parse it to extract the information you need. Process this data into a format suitable for insertion into PostgreSQL, such as a list of tuples. Here's an example of parsing daily stock prices:
```python
time_series = data['Time Series (Daily)']
records = [(date, values['1. open'], values['2. high'], values['3. low'], values['4. close'], values['5. volume']) for date, values in time_series.items()]
```

Establish a connection to your PostgreSQL database using psycopg2. Ensure you have the database credentials ready (host, database name, username, and password).
```python
import psycopg2

conn = psycopg2.connect(
host="your_host",
database="your_database",
user="your_user",
password="your_password"
)
cursor = conn.cursor()
```

Before inserting data, ensure the destination table exists. If not, create it with the appropriate schema. For example, to store daily stock data:
```python
cursor.execute("""
CREATE TABLE IF NOT EXISTS stock_data (
date DATE PRIMARY KEY,
open NUMERIC,
high NUMERIC,
low NUMERIC,
close NUMERIC,
volume BIGINT
)
""")
conn.commit()
```

Insert the processed data into the PostgreSQL table. Use the `executemany` method for efficient batch insertion, and commit the transaction to save changes:
```python
insert_query = """
INSERT INTO stock_data (date, open, high, low, close, volume)
VALUES (%s, %s, %s, %s, %s, %s)
ON CONFLICT (date) DO NOTHING
"""
cursor.executemany(insert_query, records)
conn.commit()

# Close the connection
cursor.close()
conn.close()
```

By following these steps, you can manually transfer data from Alpha Vantage to a PostgreSQL database without relying on third-party connectors or integrations.