Is there a way, when looking at a table datasheet view, to tell all the cells that have a zls and not a null?
If you're poking around tables in the normal course of using the db, that's generally not a great idea. In the very least, it offers little in the way of revealing/examining/filtering etc. your data. A query is slightly a better choice and a form is better still for normal use. In this case, a query would spot zls right away if you just want to find any that exist. Criteria would be =""
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.