Without endorsing the use of these, let's assume you have a mailing list of
friends and relatives with names, addresses, phone, emails,...
You want to be able to track these people according to different groupings
such as "Canoe Club", "Kiwanis", "Christmas Card", "Joe's Classmates",
"Church Members", ... This will hopefully allow you to forward off-color
email jokes to Joe's Classmates and not Church Members ;-)
I have seen some newbies that would create one yes/no field in the table of
people for each of the different groupings. This would be horribly
un-normalized.
The multivalued field would provide a fairly slick interface for creating a
single field in the table of people. You could drop-down a list of all groups
and check the ones that apply.
If you needed to store any other information about the person's group
membership, this would break. For instance if you wanted to add a status or
start date for the relationship between the person and the group. You
couldn't do this with a multivalue field.
I think it's best to avoid multivalue fields however they are much better
than creating multiple yes/no fields in a table.
--
Duane Hookom
Microsoft Access MVP
Jamie Collins said:
Jason Lepack said:
This may sound like a dumb question, but I really can't understand
Microsoft's explanation of how I may use Multivalued fields in Access 2007. I
think that I'm suffering from old-style Access orthodoxy. Can someone explain
a simple real-world scenario where I may use this new feature in Access 2007?
Where did you find this explanation?
The OP probably meant this one:
Using multivalued fields in queries
http://office.microsoft.com/en-us/access/HA101492971033.aspx
The OP may find the answers here:
Multivalued datatypes considered harmful
http://www.regdeveloper.co.uk/2006/07/18/multivalued_datatypes_access/print.html
"the Access Program Manager [did] convince me that the team was fully aware
of the implications of introducing this new data type. So why has Microsoft
done it? ...The first is that Microsoft is keen for Access to be compatible
with SharePoint...The second reason is that the company does seem to be
genuinely interested in making the product easier for power users to drive.
The development team feels that power users find the creation of many-to-many
joins using three tables conceptually very difficult and will find
multi-valued data types a much easier solution."
Jamie.