At 04:24 PM 20/02/2007, you wrote:

>Does the default Master Detail behaviour of datasets which auto
>synchronise on common key field names also work with DBComboLookups?
>
>I want to select a master record in one combo, and automatically
>filter the available rows for selection in a "child" combo. I can't
>get this to work.
>
>How can I do this?

You can't. Master-detail is the wrong kind of relationship to use
TDBLookupCombo for (if that's what you meant...I don't know of
"DBComboLookups"). They are incompatible.

Use this control for *lookup* relationships: where you have a key in
a set that links to a unique key in another set. In a sense, it's
the "reverse" of master-detail. M-D has a single master and
0-to-many detail records. A lookup set has a single unique entry and
0-to-many records in the "requesting" set that could match a single entry.

For example, you could use it in an address maintenance program. You
main set has records for various different addresses that you store
for some parent record. You have a field in this Address record
called "AddressType" which is an integer pointing to a table
AddressType. Your DBLookupCombo would have AddressType as its
ListSource (the place where the list of choices comes from) and
Address as its Datasource (the table that needs to choose an
AddressType). The Datafield property of the DBLookupCombo would be
AddressType in the Address record. The KeyField property would be
the primary key of the AddressType table; and the ListField would be
the Description field of the AddressType table, i.e. the one you want
to display.

Helen