Users are PASTING data into a form in DATASHEET mode, so many records are being entered at the same time. For a specific field called ID, I need to validate the ID against another table. In the sense that the IDs they enter should be already available in another table. Drop down box, selection is not possible.
I also need to return the values that are not VALID
What kind of SQL statment or VBA or validation rule should I use?
"In the sense that the IDs they enter should be already available in another table" - you need an event to trigger the check, so perhaps have them enter into a datasheet on a form rather than a back end table then you can use the various on-changed events, search online for them. In that event simply run a one-to-one query. To return "return the values that are not VALID" you simply need an unmatched query, again, search for info, it's widely documented.
