Set distinct drop-down values based on vlookup - excel

Question

Col A Col B
Fruit Grapes
Fruit Mango
Fruit Mango
Veg Carrot
Veg Brinjal
Fruit Banana
Veg Carrot
I have a similar requirement as shown in this thread
set drop-down values based on vlookup
This works fine, however now the requirement for me is in Column B there will be duplicates and the dropdown has to show only distinct values. Can any one help me with this
See file here Requirement
I want to achieve this by pure Excel formulas and not by VBA code.

Answer 1

Part 1 - This just shows how to create a unique list in a drop-down.
Here's a screenshot, but currently it requires that there is a row above the data(?). This provides a unique list of items in a Data Validation drop-down. (All the formulas below can be made easier to create by naming some ranges beforehand.)
The array formula in E2 is shown in the comment. Use Ctrl-Shift-Enter to enter an array formula, then drag this down as far as necessary - the #N/As will begin to appear at the bottom.
Gosh, it's hard to describe :). The COUNTIF essentially generates a sequence of 1s and 0s to indicate whereabouts in column B the previous (above) values in column E are positioned in column B. This sequence always starts with a 0 (for the formula in E2) because it's looking for a blank which doesn't occur in column B - so this will grab the first item, Grapes.
The MATCH then finds the first 0 in this sequence of 0s and 1s, which indicates that a value (in column B) hasn't already appeared in column E.
INDEX then uses this MATCHed value to retrieve the new unique item from column B.
Then a Defined Name is created (on the Formulas tab) that gets all the values in column E, but only down to the first occurrence of '#', which indicates there are no more unique values in the list.
This Defined Name is then used in the Data Validation.
Part 2 - The Answer (with VBA)
The following VBA code is required so that clicking in a cell in C11:C18 will change the value in F1, which generates the unique list underneath, which populates the data-validation list in C11:C18.
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Not Application.Intersect(Target, Range("C11:C18")) Is Nothing Then
Sheets("Sheet1").Range("F1").Value = ActiveCell.Offset(0, -1).Value
End If
End Sub
It requires the formulas and defined-name as shown in the following screenshot. The formula in F2 is different to F3, which is then copied down.
The number 10 in the formula in F3 is just a large number (of rows).
Column E are the unique items.
Column D are the corresponding categories.
Column F are the unique items for the category in cell F1 (extracted form column E).
Part 3 - Without VBA
Use the formula =INDIRECT(ADDRESS(CELL("row"),CELL("col")-1)) in cell F1. When you click into a cell in C11:C18 you need to press F9 to recalculate the worksheet, which updates the drop-down list.
Recalculating is necessary to update the CELL("row") and CELL("col") values.
Part 4 - Without pressing F9
It can be achieved without having to press F9, but it means spreading all the categories across different columns (G1 and to the right in the below screenshot). This can also be achieved with the array formula =INDEX($A$2:$A$8,MATCH(0,COUNTIF($F$1:F1,$A$2:$A$8),0)) in G1.
The #N/As can also be removed the the drop-down lists with strategic use of IFERROR() in the formulas from G2 onwards, substituting "". Alternatively, using:
=OFFSET(Sheet1!$G$1,1,MATCH(Sheet1!B11,Sheet1!$G$1:$J$1,0)-1,MATCH("#",OFFSET(Sheet1!$G$1,1,MATCH(Sheet1!B11,Sheet1!$G$1:$J$1,0)-1,COUNTA(Sheet1!$G:$G)-1,1),-1),1)
as the defined-name Items would not only remove the #N/As but also the redundant ("") values that IFERROR() would leave in the drop-down lists. (The cursor needs to be positioned in C11 when creating this defined-name.)
Apologies for the length of this, but hope it is of interest to someone.