Data Validation List to show unique values

[vegasbaby207]

Hi,

I regularly use INDIRECT(tablename[fieldname]") as the source formula of a data validation list to provide the end user with a quick way to select a specific row of data.
Previously, the data source has always contained unique values. I am now working with a new data source that will contain duplicates.

Is there a straightforward way to only show unique values in the dropdown list?

The table I am working with - Orders - has a field called ID - which now contains duplicates.
Not sure if it helps, but there is a column called OrderLineNumber in the same Orders table. Sample below...

ID	OrderLineNumber
85	1
85	2
85	3
85	4
86	1
86	2
87	1
88	1
89	1
89	2

 

[mabbutt]

Have a look here.

 

[vegasbaby207]

Have a look here.

Hi, thanks for the quick reply.
That was one of the options I found before posting here. Unfortunately it doesn't fit the requirements because the list of options is always growing, and the required interim step of having a list of unique items (the yellow bit on their example) won't work because the list is growing every day.

 

[mabbutt]

Just identify the range before starting so that you always have the updated range using something like this:

=ROW(OFFSET(A1,COUNTA(A:A)-1,0))