finding observations that happened at the same time

[lillymaginta]

I have the following data

id      str                date 

1      car               01/01/2004 

1      bus              01/01/2004 

2      car               02/05/2005

2      car               03/06/2006

3      car               02/02/2002

3      truck            02/02/2002 

3     car                03/03/2003

3     truck             03/03/2003 

3     car                04/04/2004

3     bus               04/04/2004 

3     truck             05/05/2005 

I want to find the frequency of id who bought items the same day where each id will be counted only once if they bought the same item's combination multiple times. 

Here is my output: 

car-bus    2

car- truck 1 

then I want to find those who bought only one item (each id counted once)

car 1 

truck 1 

Thanks! 

[Haikuo · Accepted solution]

This will require multiple steps, I can't say I am 100% confident in term of understanding what you need, but here is a try, please let us know if it fits your bill:

data have;
	input id      str :$8.               date: mmddyy10.;
	cards;
1      car               01/01/2004 
1      bus              01/01/2004
2      car               02/05/2005
2      car               03/06/2006
3      car               02/02/2002
3      truck            02/02/2002 
3     car                03/03/2003
3     truck             03/03/2003 
3     car                04/04/2004
3     bus               04/04/2004 
3     truck             05/05/2005 
;

/*sort and dedup*/
proc sort data=have out=h_sort nodupkey;
	by id date str;
run;

/*creat group variable*/
data h_grouping;
	do until (last.date);
		set h_sort;
		by id date str;
		length group $ 100;
		group=catx('-',group,str);
	end;
run;

/*count*/
proc sql;
	select group, count(distinct id) as id_ct from
		h_grouping
	group by group
	;
quit;

[lillymaginta]

thank you, works!