Connect an application

YSQL
YCQL

The following tutorial creates a basic Python application that connects to a YugabyteDB cluster using the aiopg database adapter, performs a few basic database operations — creating a table, inserting data, and running a SQL query — and prints the results to the screen.

Prerequisites

Before you start using Aiopg, ensure you have the following:

YugabyteDB up and running. If you are new to YugabyteDB, follow the steps in Quick start to have YugabyteDB up and running in minutes.
Python 3, or later, is installed.
aiopg package is installed. Install the package using the following command:
```
pip3 install aiopg
```
For details about using this database adapter, see aiopg documentation.

Create the sample Python application

Create a file yb-sql-helloworld.py and copy the following code:


import asyncio
import aiopg

dsn = 'dbname=yugabyte user=yugabyte password=yugabyte host=127.0.0.1 port=5433'


async def go():
    async with aiopg.create_pool(dsn) as pool:
        async with pool.acquire() as conn:
            # Open a cursor to perform database operations.
            async with conn.cursor() as cur:
                await cur.execute(f"""
                  DROP TABLE IF EXISTS employee;
                  CREATE TABLE employee (id int PRIMARY KEY,
                             name varchar,
                             age int,
                             language varchar);
                """)
                print("Created table employee")
                # Insert a row.
                await cur.execute("INSERT INTO employee (id, name, age, language) VALUES (%s, %s, %s, %s)",
                                  (1, 'John', 35, 'Python'))
                print("Inserted (id, name, age, language) = (1, 'John', 35, 'Python')")

                # Query the row.
                await cur.execute("SELECT name, age, language FROM employee WHERE id = 1")
                async for row in cur:
                    print("Query returned: %s, %s, %s" % (row[0], row[1], row[2]))


loop = asyncio.get_event_loop()
loop.run_until_complete(go())

Run the application

To use the application, run the following Python script:


python yb-sql-helloworld.py

You should see the following output:

Created table employee
Inserted (id, name, age, language) = (1, 'John', 35, 'Python')
Query returned: John, 35, Python