Hi, I need to write a SQL for the below scenario. Please help.
Need to write a select SQL to fetch the invalid one with mark NA, along with the valid one here.

In the above data till the student takes any test after a Model Exam, its marks hold good.
When he takes any test after the model exam, then I need to update the mark as NA.
ie, the marks for the model exam should be the final. If he tries to take any test after the model exam, I need to mark its score as NA.
Regards
MUS