I see that you went against the advice given in your last post.  I'm afraid that is not supported here as the MVF is on the Evil Access Stuff list and most of us just don't use it.  This is one of the reasons why.  They are notoriously difficult to work with.

If you haven't already watched it check out the Multivalued video.

A better alternative is using a Many-to-Many relationship.

To clear all values in a multivalue field named MVField1 in a record identified by the primary key ID1, run this query:

     DELETE FROM Table1.MVField1.Value WHERE Table1.ID = ID1

You can't do it in the query designer.  You have to manually edit the SQL.

P.S.  Hi Scott, yes, multivalue fields can be challenging, but in certain cases they can help greatly.  The biggest hurdles are queries.  If the user can overcome the challenges of making delete queries (which isn't so bad above) and append queries, then MVFs are a viable solution.  The one big caveat is that SQL Server doesn't support MVFs.  If you anticipate migrating to SQL Server, that's a no can do.

And here is what an update query looks like.  To insert the value "ABC" to the multivalue field that belongs to a record with primary key 1:

     INSERT INTO Table1 ( MYField1.Value )
     SELECT "ABC" AS Expr1
     FROM Table1
     WHERE Table1.ID=1;

Note that this can insert values that aren't in the combo box.  Even if your combo box is set to "Limit to List", it will still accept such nonexistent values.  After the update, such values will even show up in your combo box with checkmarks next to them.  Uncheck them and they'll be gone, like before.  This is another caveat that gives people pause.

My head is hurting (It's me not you guys)

Ok, I have a button called "Enter" on a form that I set up to open a form and also run an update query to clear the field "Required"

I have a table "Sub Risks" which has an MVF called "Harmed" which has three entries, Contractor, Employee and Public.

Every time I click the "Enter" button I want the MVF fields to be deleted, so when the new form opens the MVF field is back to a state of Null

Now I have been opening the Event procedure for the "Enter" button and adding the above code from Kevin ( and changing what I think needs changing) and I am getting nowhere, can you help please?

Sorry, the delete query should be below, a slight correction on the syntax:

     DELETE Table1.MVField1.Value FROM Table1 WHERE Table1.ID = ID1

How familiar are you with queries in general?  Working with MVF inside queries is tricky, so a good knowledge on queries is best.  For instance, queries that update MVFs cannot update non-MVFs.  Yet another caveat.

So my code would look like this:

    DELETE Sub Risk.Harmed.Value FROM Sub Risk WHERE Sub Risk.ID = ID1

I am not very experienced with Access at all, just starting out.

so do I enter the Event procedure for the @Enter@ button and add this line into it?

Forgot to mention, I am trying to clear all entries in the Colum "harmed" not just one record

To delete all MVF values in all records, remove the WHERE clause:

     DELETE Table1.MVField1.Value FROM Table1

If you have spaces in your table name, you need to enclose it with square brackets:

    DELETE [Sub Risk].Harmed.Value ...

It's generally not advisable to have spaces in tables names and field names, because you don't want to use [ and ] all the time.

You use the button's Click event.  Event procedures use VBA.  To run the delete query in VBA, you need to write it in a way that conforms to VBA's rules:

    CurrentDb.Execute "DELETE Table1.MVField1.Value FROM Table1"

All this requires some knowledge on SQL, VBA, table design and naming conventions, etc.  It's best to take some beginner's courses on these first.  You can keep asking me questions, but you may achieve your goals (a lot) faster with some courses.

Kevin, thank you so much for your time and understanding, I have no managed to set it all up