If there is a very good reason to understand the Data Manipulation API, it is for the compatibility methods provided by the class that ensures that your ‘singing and dancing’ plugin works with all the Moodle supported database engines and the numerous query shortcuts that just make life easier.
This video has UK English subtitles and if you struggle with English or even with my accent, you can use YouTube’s auto-translate functionality to view the subtitles in your preferred language.
This video is an extract from the ‘Moodle Plugins By Example’ course – go to the Course Page for more details.