In this chapter, we will cover the following recipes:

• Using external IDs and namespaces
• Loading data using XML files
• Using the noupdate and forcecreate flags
• Loading data using CSV files
• Add-on updates and data migration
• Deleting records from XML files
• Invoking functions from XML files

In order to avoid repeating a lot of code, we'll make use of the models that were defined in Chapter 5, Application Models. To follow these examples, make sure you grab the code for the my_library module from Chapter05/r6_ hierarchy_model/my_library.