Merging data

[hovliza]

When I want to merge 6 datasets to one dataset like this:

*Merge datasets*;
DATA m.combined;
MERGE 	m.dataset1
	m.dataset2
	m.dataset3
	m.dataset4 
	m.dataset5
	m.dataset6; 
BY personnumber;
RUN;

Why do I get in my output table 3 times the same measurements for my personnumber like this:

Personnumber	Gender	Heigth	Weight
1	1	167	56
1	1	167	56
1	1	167	56
2	1	188	78
2	1	188	78
2	1	188	78
3	2	190	102
3	2	190	102
3	2	190	102

I want to merge it like this:

Personnumber	Gender	Heigth	Weight
1	1	167	56
2	1	188	78
3	2	190	102

There are no errors, so can someone please help? Thanks!

[Kurt_Bremser]

It's in the data. Please post your datasets (in data steps).

[hovliza]

What do you mean? I can't post my whole dataset here..

[Kurt_Bremser]

Just post the data (in all datasets) for persons 1, 2 and 3 (as mentioned in your original question).

[Astounding]

One of your incoming data sets (OK, possibly more than one) already contains multiple observations for each PERSONNUMBER.  You have to fix that data set first (again, possibly more than one data set to fix) if you want to end up with one observation apiece.

If you think it's legitimate that one of your incoming data sets contains multiple observations per personnumber, then you need to decide what should happen with those ... how can your input contain many, but your output only one?  What is the process to go through to narrow down the observations?