Hi Aris,

Out of the columns that can be made null, only some of the columns facilitate nullifying a value with grid editing. 
For example, while columns rating and special_features of sakila.film can be made null with grid editing, release_year and length of the same table cannot be made null. 
I feel it would be better if the behavior is consistent among all the columns that can be made null.

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Thanks and Regards,

Madhura Jayaratne