Updating Data with Sessions
Establishing a Session
After a mapping class is defined and a connection is established, the session is used to modify data in the available tables. The session is initially obtained by performing the below:
engine = create_engine("cdata_DB2:///?Server=10.0.1.2;Port=50000;User=admin;Password=admin;Database=test") factory = sessionmaker(bind=engine) session = factory()
First, define an instance of the mapped class, then add it to the active session. Call "commit()" on the session to push all added instances as inserted rows.
new_rec = Books(Id="22", Id="Jon Doe", Author="John") session.add(new_rec) session.commit()
First, fetch the desired records with a filtered query. Then, modify the values of their fields and call "commit()" to update any records modified in this way.
modded_rec = session.query(Books).filter_by(Id="22").first() modded_rec.Id = "Jon Doe" modded_rec.Author = "John" session.commit()
First, fetch the desired records with a filtered query, then delete with the session. Call "commit()" to perform the delete operation with the provided rows.
removed_rec = session.query(Books).filter_by(Id="22").first() session.delete(removed_rec) session.commit()