Generate Sequence number for each group

[jhh197]

Hi ,

I have a dataset that has gnp,cnp idnb for each of these we have Cplus and Cccare and each one has 3 p1_lmt and 3 P2_LMT values and out of that i need the first P1_LMT and 1st P2_LMT and need to generate a column Seq as shown below .

So i can pick up only seq = 1 for every gnp,cnp,idnb,type combination 

gnp	cnp	idnb	Type	P1_LMT	P2_LMT	Amount	Seq
56000	3200	520	Cplus	0	0	10	1
56000	3200	520	Cplus	1	3	20	2
56000	3200	520	Cplus	50	250	30	3
56000	3200	520	Ccare	0	0	40	1
56000	3200	520	Ccare	1	3	67	2
56000	3200	520	Ccare	50	250	90	3
345670	5674	520	Cplus	1	25	10	1
345670	5674	520	Cplus	25	250	20	2
345670	5674	520	Cplus	250	500	30	3
345670	5674	520	Ccare	1	25	40	1
345670	5674	520	Ccare	25	250	67	2
345670	5674	520	Ccare	250	500	90	3

Can anyone please help 

[Kurt_Bremser]

data want;
set have;
by gnp cnp idnb type;
if first.type
then seq = 1;
else seq + 1;
run;

[jhh197]

Thank you so much for all your help . Both the solutions work . Just wanted to understand what is the difference between two solutions 

[s_lassen · Accepted solution]

data want;
  do seq=1 by 1 until(last.type);
    set have;
    by gnp cnp idnb type;
    output;
    end;
run;

[jhh197]

Thank you so much for all your help . Both solutions are working