checkdata management command:
Update the table of data problems.
If no arguments are given, run it on all data checkers. Otherwise every positional argument is expected to be a model name in the form app_label.ModelName, and only these models are being updated.
In other words, this command does the same as if a user would click on the button with the bell ("Check data") on each database object for which there are data checkers.
(This module's source code is available here.)