Which Formula to use for data consolidation?

jrubin 

Let's say your table data range is A4:G19 (Headers are in A3:G3).

Then you can enter formula below in H4 and copy down:

=SUMIFS($F$4:$F$19,$A$4:$A$19,A4,$B$4:$B$19,B4,$C$4:$C$19,C4)

This formula sums up the Total Orders Placed for all customers with same First Name, Last Name and Date of Birth. Formula can be adapted to larger ranges and you can delete criteria for Date of Birth if you want to. In the example i include Date of Birth as there are people with same First Name and Last Name.

Enter formula below in I4 to sum Total Sales:

=SUMIFS($G$4:$G$19,$A$4:$A$19,A4,$B$4:$B$19,B4,$C$4:$C$19,C4)  

I would enter this formula below in J4 in order to return TRUE if a customer appears two or more times in the dataset:

=COUNTIFS($A$4:$A$19,A4,$B$4:$B$19,B4,$C$4:$C$19,C4)>=2

After that copy and paste only values for columns that contain formulas (H, I and J in this example) and then sort table by columns A, B and C and delete double entries.