Use the create_context() function to create a connection to Vantage using the teradatasql and teradatasqlalchemy DBAPI and dialect combination.
You can pass all required arguments (host, username, password) to establish a connection to Vantage, or pass a sqlalchemy engine to the tdsqlengine parameter to override the default DBAPI and dialect combination. You can create connection to Vantage enabled with various security mechanisms.
The optional logdata argument specifies parameters to the LOGMECH command beyond those needed by the logon mechanism, such as user ID, password and tokens (in case of JWT) to successfully authenticate the user.
The optional database argument specifies the initial database to use after log on, instead of your default database.
In case you do not have permissions to create tables or views in your own database, but are allowed to create the required objects in other common database, you must use the argument temp_database_name to pass the name of the other database where temporary tables and views will be created. If this argument is not provided, intermediate database objects are created in your default database.
| Arguments provided | Where the actions are done | ||
|---|---|---|---|
| temp_database_name | database | Internal temporary objects are created in | Database object (table or view) lookup is done from |
| Yes | Yes | temp_database_name | database |
| No | Yes | database | database |
| Yes | No | temp_database_name | User's default database |
| No | No | User's default database | User's default database |
These permissions allow the user to:
- Create tables and views to save results of teradataml analytic functions;
- Create views in the background for results of DataFrame APIs such as 'assign()', 'filter()', etc., whenever the result for these APIs are accessed using a 'print()';
- Create views in the background on the query passed to the 'DataFrame.from_query()' API.
It is expected that the user has the correct permissions to create these objects in the database to be used.
The access to the views created may also require issuing additional GRANT SELECT ... WITH GRANT OPTION permission depending on which database is used and which object the view being created is based on.
The following examples section demonstrates passing encrypted password to the password argument.
For more information on Stored Password Protection and how to generate key and encrypted password file used in examples, see the Stored Password Protection section under the teradatasql project, on https://pypi.org/user/teradata/.
See Garbage Collection in teradataml for more details.
For more information, see Teradata Vantage™ - Advanced SQL Engine Security Administration.
Example: Create a context using hostname, username and password
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', username='tduser', password = 'tdpassword')
Example: Create a context using already created sqlalchemy engine
>>> from sqlalchemy import create_engine
>>> sqlalchemy_engine = create_engine('teradatasql://'+ tduser +':' + tdpassword + '@'+tdhost
>>> from teradataml.context.context import * >>> create_context(tdsqlengine = sqlalchemy_engine)
Example: Create a context with default logmech 'TD2'
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', username='tduser', password = 'tdpassword', logmech='TD2')
Example: Create a context with default logmech 'TDNEGO'
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', username='tduser', password = 'tdpassword', logmech='TDNEGO')
Example: Create a context with default logmech 'LDAP'
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', username='tduser', password = 'tdpassword', logmech='LDAP')
Example: Create a context with default logmech 'KRB5'
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', logmech='KRB5')
Example: Create a context with default logmech 'JWT'
>>> from teradataml.context.context import * >>> create_context(host = 'tdhost', logmech='JWT', logdata='token=eyJpc...h8dA')
Example: Create a context using encrypted password and key passed to the 'password' argument
ENCRYPTED_PASSWORD(file:<PasswordEncryptionKeyFileName>, file:<EncryptedPasswordFileName>)Where:
- PasswordEncryptionKeyFileName specifies the name of a file that contains the password encryption key and associated information
- EncryptedPasswordFileName specifies the name of a file that contains the encrypted password and associated information.
>>> td_context = create_context(host = 'tdhost', username='tduser', password = "ENCRYPTED_PASSWORD(file:PassKey.properties, file:EncPass.properties)")
Example: Create a context using encrypted password in LDAP logon mechanism
>>> td_context = create_context(host = 'tdhost', username='tduser', password = "ENCRYPTED_PASSWORD(file:PassKey.properties, file:EncPass.properties)", logmech='LDAP')
Example: Create a context to connect to a different initial database, using hostname, username and password
This example creates a context using hostname, username and password, and connect to a different initial database by setting the database argument.
>>> td_context = create_context(host = 'tdhost', username='tduser', password = 'tdpassword', database = 'database_name')
Example: Creates a context to connect to a different initial database, using already created sqlalchemy engine
This example creates a context using already created sqlalchemy engine, and connect to a different initial database by setting the database argument.
>>> from sqlalchemy import create_engine
>>> sqlalchemy_engine = create_engine('teradatasql://'+ tduser +':' + tdpassword + '@'+tdhost + '/?DATABASE=database_name')
>>> create_context(tdsqlengine = sqlalchemy_engine)
Example: Create a context to connect to a different initial database, using 'LDAP' logmech
This example creates a context with 'LDAP' logmech, and connect to a different initial database by setting the database argument.
>>> td_context = create_context(host = 'tdhost', username='tduser', password = 'tdpassword', logmech='LDAP', database = 'database_name')