Excel: Index-Match using keywords and then SUM results (no VBA) - excel

Question

I've got a sheet with a transaction list. It includes a description of the transaction and the transaction total cost.
I'm looking for a way, without using Visual Basic, to use comma-separated keywords entered in a cell to search for all matching transactions, and then give their total value.
For example:
B4:B6 are keywords for look up.
C4 should look up in range B10:B26 for all cells containing any of the keywords in B1 (tesco OR co-op OR waitrose), and return the total value of the corresponding values in Range C10:C26. In this case it should SUM C11, C16, C21, C23, C25.
It's important to note that it shouldn't be case sensitive.
Can it be done?

Answer 1

You can do this with Array Functions. These functions operate similarly to "Sumifs" / "Countifs" / "Sumproduct": they perform functions normally designed to look at a specific cell, over an entire range of cells.
First let's deal with summing the total for "giffgaff" / "paypal":
In cell C5, use the following formula [As it is an Array formula, you must confirm by pressing CTRL + SHIFT + ENTER every time you edit the cell, instead of just ENTER] , and drag down to C6.
=sum(if(iserror(search(B5,$B$10:$B$26)),"",$C$10:$C26))
This looks at each row from B10:B26 (note that the entire column cannot be selected as an array formula calculates for all cells, even blank ones - so this drastically slows performance. You must specifically identify the rows you care about like this), and if there is an error when trying to search for the term in B4, that means the term does not appear on that particular row. If there is no error, it pulls the amount from column C. All of these rows are then summed together to get a single total.
Now to do the same for cell C4, you need to add in the complexity of first pulling apart each term which appears between a comma. I agree that #Tom Sharpe that you should probably do this in different cells to make it more clear what you're doing. This could be done by individually pulling terms between commas, and then having individual totals (which use the array formula above).
To do this most efficiently, I'd have use a helper column in column C, which will identify how many commas are in the text in column B, like so, in C4:
=len(B4)-len(substitute(B4,",",""))
This takes the length of B4, less the length of B4 where all commas have been replaced by blanks - giving the # of commas.
That formula can then be used to split out the words between commas, using the MID and SUBSTITUTE functions. Let me know if you need elaboration on how to do that. Once you have broken out the individual words, you can search with the Array function as above.