sum cumulative by date

[Geo-]

how to use data step or sql to achieve this.any suggestions or ideas ?

thanks!

orignial data:

date	spend
20180801	5
20180801	4
20180802	3
20180802	7
20180802	1
20180803	0.5

want:

date	sumCumulative
20180801	9
20180802	20
20180803	20.5

logic:

date	cumulativeSum
20180801	5+4
20180802	5+4+3+7+1
20180803	5+4+3+7+1+0.5

[Kurt_Bremser]

Please supply example data in a usable form (datastep with datalines), and show the expected output.

You can't have two columns with the same name in a dataset.

[Ksharp · Accepted solution]

data have;
infile cards expandtabs;
input date	spend;
cards;
20180801	5	 	 	20180801	5+4
20180801	4	 	 	20180802	5+4+3+7+1
20180802	3	 	 	20180803	5+4+3+7+1+0.5
20180802	7	 	 	 	 
20180802	1	 	 	 	 
20180803	0.5
;
run;
proc summary data=have;
by date;
var spend;
output out=temp sum=;
run;
data want;
 set temp;
 sum+spend;
run;

[novinosrin]

data have;
infile cards expandtabs;
input date	spend;
cards;
20180801	5	 	 	20180801	5+4
20180801	4	 	 	20180802	5+4+3+7+1
20180802	3	 	 	20180803	5+4+3+7+1+0.5
20180802	7	 	 	 	 
20180802	1	 	 	 	 
20180803	0.5
;
run;

data want;
do until(last.date);
set have;
by date;
sum+spend;
end;
run;