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Use SQLAlchemy ORMs to Access Microsoft CDS Data in Python

The CData Python Connector for Microsoft CDS enables you to create Python applications and scripts that use SQLAlchemy Object-Relational Mappings of Microsoft CDS data.

The rich ecosystem of Python modules lets you get to work quickly and integrate your systems effectively. With the CData Python Connector for Microsoft CDS and the SQLAlchemy toolkit, you can build Microsoft CDS-connected Python applications and scripts. This article shows how to use SQLAlchemy to connect to Microsoft CDS data to query, update, delete, and insert Microsoft CDS data.

With built-in optimized data processing, the CData Python Connector offers unmatched performance for interacting with live Microsoft CDS data in Python. When you issue complex SQL queries from Microsoft CDS, the CData Connector pushes supported SQL operations, like filters and aggregations, directly to Microsoft CDS and utilizes the embedded SQL engine to process unsupported operations client-side (often SQL functions and JOIN operations).

Connecting to Microsoft CDS Data

Connecting to Microsoft CDS data looks just like connecting to any relational data source. Create a connection string using the required connection properties. For this article, you will pass the connection string as a parameter to the create_engine function.

You can connect without setting any connection properties for your user credentials. Below are the minimum connection properties required to connect.

  • InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
  • OrganizationUrl: Set this to the organization URL you are connecting to, such as https://myorganization.crm.dynamics.com.
  • Tenant (optional): Set this if you wish to authenticate to a different tenant than your default. This is required to work with an organization not on your default Tenant.

When you connect the Common Data Service OAuth endpoint opens in your default browser. Log in and grant permissions. The OAuth process completes automatically.

Follow the procedure below to install SQLAlchemy and start accessing Microsoft CDS through Python objects.

Install Required Modules

Use the pip utility to install the SQLAlchemy toolkit:

pip install sqlalchemy

Be sure to import the module with the following:

import sqlalchemy

Model Microsoft CDS Data in Python

You can now connect with a connection string. Use the create_engine function to create an Engine for working with Microsoft CDS data.

engine = create_engine("cds///?OrganizationUrl=https://myaccount.crm.dynamics.com/InitiateOAuth=GETANDREFRESH&OAuthSettingsLocation=/PATH/TO/OAuthSettings.txt")

Declare a Mapping Class for Microsoft CDS Data

After establishing the connection, declare a mapping class for the table you wish to model in the ORM (in this article, we will model the Accounts table). Use the sqlalchemy.ext.declarative.declarative_base function and create a new class with some or all of the fields (columns) defined.

base = declarative_base()
class Accounts(base):
	__tablename__ = "Accounts"
	AccountId = Column(String,primary_key=True)
	Name = Column(String)
	...

Query Microsoft CDS Data

With the mapping class prepared, you can use a session object to query the data source. After binding the Engine to the session, provide the mapping class to the session query method.

Using the query Method

engine = create_engine("cds///?OrganizationUrl=https://myaccount.crm.dynamics.com/InitiateOAuth=GETANDREFRESH&OAuthSettingsLocation=/PATH/TO/OAuthSettings.txt")
factory = sessionmaker(bind=engine)
session = factory()
for instance in session.query(Accounts).filter_by(Name="MyAccount"):
	print("AccountId: ", instance.AccountId)
	print("Name: ", instance.Name)
	print("---------")

Alternatively, you can use the execute method with the appropriate table object. The code below works with an active session.

Using the execute Method

Accounts_table = Accounts.metadata.tables["Accounts"]
for instance in session.execute(Accounts_table.select().where(Accounts_table.c.Name == "MyAccount")):
	print("AccountId: ", instance.AccountId)
	print("Name: ", instance.Name)
	print("---------")

For examples of more complex querying, including JOINs, aggregations, limits, and more, refer to the Help documentation for the extension.

Insert Microsoft CDS Data

To insert Microsoft CDS data, define an instance of the mapped class and add it to the active session. Call the commit function on the session to push all added instances to Microsoft CDS.

new_rec = Accounts(AccountId="placeholder", Name="MyAccount")
session.add(new_rec)
session.commit()

Update Microsoft CDS Data

To update Microsoft CDS data, fetch the desired record(s) with a filter query. Then, modify the values of the fields and call the commit function on the session to push the modified record to Microsoft CDS.

updated_rec = session.query(Accounts).filter_by(SOME_ID_COLUMN="SOME_ID_VALUE").first()
updated_rec.Name = "MyAccount"
session.commit()

Delete Microsoft CDS Data

To delete Microsoft CDS data, fetch the desired record(s) with a filter query. Then delete the record with the active session and call the commit function on the session to perform the delete operation on the provided recoreds (rows).

deleted_rec = session.query(Accounts).filter_by(SOME_ID_COLUMN="SOME_ID_VALUE").first()
session.delete(deleted_rec)
session.commit()

Free Trial & More Information

Download a free, 30-day trial of the Microsoft CDS Python Connector to start building Python apps and scripts with connectivity to Microsoft CDS data. Reach out to our Support Team if you have any questions.