Quickstart: Connect with the pyodbc driver for Python

In this quickstart, you connect a Python script to a database that you created and loaded with sample data. You use the pyodbc driver for Python to connect to your database and perform basic operations, like reading and writing data.

pyodbc documentation | pyodbc source code | Package (PyPi)

Prerequisites

• Python 3

  • If you don't already have Python, install the Python runtime and Python Package Index (PyPI) package manager from python.org.

  • Prefer to not use your own environment? Open as a devcontainer using GitHub Codespaces.

    

• pyodbc package from PyPI.

• A database on SQL Server, Azure SQL Database, or SQL database in Fabric with the AdventureWorks2022 sample schema and a valid connection string.

Setting up

Follow these steps to configure your development environment to develop an application using the pyodbc Python driver.

Install the pyodbc package

Get the pyodbc package from PyPI.

1. Open a command prompt in an empty directory.

2. Install the pyodbc package.

   pip install pyodbc
   

Install python-dotenv package

Get the python-dotenv from PyPI.

1. In the same directory, install the python-dotenv package.

   pip install python-dotenv
   

Check installed packages

You can use the PyPI command-line tool to verify that your intended packages are installed.

1. Check the list of installed packages with pip list.

   pip list
   

Create a SQL database

This quickstart requires the AdventureWorks2022 Lightweight schema, on Microsoft SQL Server, SQL database in Fabric or Azure SQL Database.

Run the code

• Create a new file
• Execute a query
• Insert a row as a transaction

Create a new file

1. Create a new file named app.py.

2. Add a module docstring.

   """
   Connects to a SQL database using pyodbc
   """
   

3. Import the pyodbc package.

   from os import getenv
   from dotenv import load_dotenv
   from pyodbc import connect
   

4. Use the pyodbc.connect function to connect to a SQL database.

   load_dotenv()
   conn = connect(getenv("SQL_CONNECTION_STRING"))
   

5. In the current directory, create a new file named .env.

6. Within the .env file, add an entry for your connection string named SQL_CONNECTION_STRING. Replace the example here with your actual connection string value.

   SQL_CONNECTION_STRING="Driver={ODBC Driver 18 for SQL Server};Server=<server_name>;Database={<database_name>};Encrypt=yes;TrustServerCertificate=no;Authentication=ActiveDirectoryInteractive"
   

   Tip

   The connection string used here largely depends on the type of SQL database you're connecting to. If you're connecting to an Azure SQL Database or a SQL database in Fabric, use the ODBC connection string from the connection strings tab. You might need to adjust the authentication type depending on your scenario. For more information on connection strings and their syntax, see connection string syntax reference.

Execute a query

Use a SQL query string to execute a query and parse the results.

1. Create a variable for the SQL query string.

   SQL_QUERY = """
   SELECT
   TOP 5 c.CustomerID,
   c.CompanyName,
   COUNT(soh.SalesOrderID) AS OrderCount
   FROM
   SalesLT.Customer AS c
   LEFT OUTER JOIN SalesLT.SalesOrderHeader AS soh ON c.CustomerID = soh.CustomerID
   GROUP BY
   c.CustomerID,
   c.CompanyName
   ORDER BY
   OrderCount DESC;
   """
   

2. Use cursor.execute to retrieve a result set from a query against the database.

   cursor = conn.cursor()
   cursor.execute(SQL_QUERY)
   

   Note

   This function essentially accepts any query and returns a result set, which can be iterated over with the use of cursor.fetchone().

3. Use cursor.fetchall with a foreach loop to get all the records from the database. Then print the records.

   records = cursor.fetchall()
   for r in records:
       print(f"{r.CustomerID}\t{r.OrderCount}\t{r.CompanyName}")
   

4. Save the app.py file.

5. Open a terminal and test the application.

   python app.py
   

   Here's the expected output.

   29485   1       Professional Sales and Service
   29531   1       Remarkable Bike Store
   29546   1       Bulk Discount Store
   29568   1       Coalition Bike Company
   29584   1       Futuristic Bikes
   

Insert a row as a transaction

Execute an INSERT statement safely and pass parameters. Passing parameters as values protects your application from SQL injection attacks.

1. Add an import for randrange from the random library to the top of app.py.

   from random import randrange
   

2. At the end of app.py add code to generate a random product number.

   productNumber = randrange(1000)
   

   Tip

   Generating a random product number here ensures that you can run this sample multiple times.

3. Create a SQL statement string.

   SQL_STATEMENT = """
   INSERT SalesLT.Product (
   Name,
   ProductNumber,
   StandardCost,
   ListPrice,
   SellStartDate
   ) OUTPUT INSERTED.ProductID
   VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP)
   """
   

4. Execute the statement using cursor.execute.

   cursor.execute(
       SQL_STATEMENT,
       (
           f'Example Product {productNumber}',
           f'EXAMPLE-{productNumber}',
           100,
           200
       )
   )
   

5. Fetch the first column of the single result using cursor.fetchval, print the result's unique identifier, and then commit the operation as a transaction using connection.commit.

   resultId = cursor.fetchval()
   print(f"Inserted Product ID : {resultId}")
   conn.commit()
   

   Tip

   Optionally, you can use connection.rollback to roll back the transaction.

6. Close the cursor and connection using cursor.close and connection.close.

   cursor.close()
   conn.close()
   

7. Save the app.py file and test the application again.

   python app.py
   

   Here's the expected output.

   Inserted Product ID : 1001
   

Next step

Visit the pyodbc driver GitHub repository for more examples, to contribute ideas or report issues.