Connect and run SQL queries to an Oracle database from Python

Summary

Connecting to Oracle databases from Python provides the ability to run essential SQL queries that can be used in geoprocessing tasks.

Instructions provided describe how to connect to an Oracle database and run SQL queries from a Python script.

Procedure

1. Download and install the appropriate cx_Oracle module for the installed Python release (for example, Python 2.6, 2.7, etc.):
   • ​Download
   • Installation instructions
2. Import the module in the Python script:

import cx_Oracle

Note:
Ensure that you have fulfilled the prerequisites described the Overview section of the installation instructions, and have downloaded and installed the Oracle Client Libraries before making a connection to the database.

3. Make a connection to an Oracle database by passing in the appropriate user/password to the following connection string:

connection = cx_Oracle.connect('sde/sde@orcl')

Note:
If an error is returned containing the message "Error: No module named cx_Oracle", verify the installation of the cx_Oracle module.

4. Define a parameter to access the cursor method. This parameter connects to the Oracle instance:

cursor = connection.cursor()

5. Create a query string:

querystring = "select * from Parcels"

6. Pass the query string to the cursor method:

cursor.execute(querystring)