Aggregate Table with Numbers.app I have a table featuring some outcome (column B) versus the day it happened (column A):  



and I would like to produce another table with the unique dates in the first column and the total outcome of the day in the second column, looking like this:



I want the aggregated table to update itself automatically as new data are added to the first table, and I therefore tried to do it using formulae but it evaded me.
The formula for the right column of your aggregate table is:

=SUMIF(Data::A,A1,Data::B)


The parameters to SUMIF are:


The column of dates which you wish to group by.
The individual date you wish to output the sum of (i.e. the cell to the left).
The column which you are taking the sum of for the group.