Get Unique data from excel by button click? - vba

Question

I am new to excel macros. need some help from you.I have a excel file with 2 sheets.
in sheet one i have some data
In second sheet i need a button which will fetch the distinct C column(Mname) and their ID.

Answer 1

Like most Excel problems, this can be done with a macro, but could also be done with just formulas. Macros are often more trouble than they're worth, so here's the formula option. There are some interesting downsides to using formulas in this way, mainly that if you do too much in a single workbook, calculation will be very slow. But as long as you're dealing with less than a few thousand rows, it shouldn't be a problem.
On your primary worksheet, enter this formula in D2, and then drag it to auto-fill down however many rows you forsee using. When you're done, you can hide column D, if it suits you.
=IF(COUNTIF($C:$C,$C2)<2,MAX($D$1:$D1)+1,0)
The COUNTIF formula looks for how many elements in column C match the contents of $C2 (where $C2 is a (partially) relative reference, so the row number will change when you auto-fill into other rows). If the count is less than 2 (the element in $C2 is unique), then the IF formula returns an index number: 1 for the first unique element in the column, 2 for the second, so on. All cells in column D where the corresponding cell in C is not unique are filled with 0.
On your second sheet, you will fill columns A and B with 'lookup' formulas, searching for positive values in column D of the primary sheet. Most people use VLOOKUP() for lookups, I prefer a combination of INDEX() and MATCH(). And here's a great example of why, since our 'unique index' is not in the first column of the primary sheet (so VLOOKUP wouldn't work!).
=IFERROR(INDEX('Primary Sheet'!$A:$A,MATCH(ROW(A2)-1,'Primary Sheet'!$D:$D,0)),"")
and for the 'Mname' column of the second sheet,
=IFERROR(INDEX('Primary Sheet'!$C:$C,MATCH(ROW(B2)-1,'Primary Sheet'!$D:$D,0)),"")
These lookup formulas are based on their own row number. So the formula in cell A2 is looking for the row in column D of Primary Sheet that contains the unique index 2-1=1. The formula in A3 looks for the index 3-1=2, etc. The IFERROR() formula that is wrapped around the lookup formula ensures that if the sought-after index is not found, the formula returns an empty string (""), which looks like a blank cell. This way you can prepare a large number of rows on your secondary sheet with these lookup formulas. And if there are only a small number of unique Mnames on Primary Sheet, your secondary sheet won't have columns full of #N/A errors.