topic Re: How to merge part of a dataset with another dataset in SAS Procedures

How to merge part of a dataset with another dataset

m1986MM — Tue, 25 Nov 2014 02:37:31 GMT

Hello everyone,

I want to merge two datasets, having a common variable. However, I don't want them to merge completely. For example, the first dataset is like this:

Table 1
StudentID	Date	Test_Score1	TEST_score2	test_score3
*	*	*	*	*

The other dataset contains these variables:

Table 2
StudentID	Field_of_interest	Undergradute_field	Master_field
$	$	$	$

The studentID is the common variable. But I want to add just one variable (Field_of_interest) from table 2 to table one. Is there any way to not merge two tables completely?

I appreciate any suggestion.

Re: How to merge part of a dataset with another dataset

PGStats — Tue, 25 Nov 2014 02:48:52 GMT

The simplest way is with proc SQL :

proc sql;

create table Table_3 as

select Table_1.*, Table_2.Field_of_interest

from Table_1 left join Table_2

on Table_1.StudentID=Table_2.StudentID;

quit;

Re: How to merge part of a dataset with another dataset

m1986MM — Tue, 25 Nov 2014 03:22:10 GMT

Thanks. But this code will merge all the datasets together.

Re: How to merge part of a dataset with another dataset

Reeza — Tue, 25 Nov 2014 03:46:46 GMT

Then you haven't tried it...

Re: How to merge part of a dataset with another dataset

m1986MM — Tue, 25 Nov 2014 03:59:44 GMT

Yes, that's right.

Re: How to merge part of a dataset with another dataset

naveen20jan — Tue, 25 Nov 2014 10:31:21 GMT

Hi , you can use below part of code too.

data want ;
merge t1 (in = a)
t2 (in = b keep = StudentID Field_of_interest );
by StudentID ;
if a ;
run;

Re: How to merge part of a dataset with another dataset

m1986MM — Thu, 27 Nov 2014 03:48:03 GMT

Hi again,

I have a question about the mechanism of this code and appreciate if you can help me. When I merge the datasets by using proc sql, for example in this specific code, those observations in table 1 with the missing value of table 2 (Field_of _interest) would be deleted or not?

Thanks.

Re: How to merge part of a dataset with another dataset

PGStats — Thu, 27 Nov 2014 03:53:22 GMT

All observations from Table 1 will be included, even those without a matching record in Table 2. If you want to keep only matching records, replace left join with inner join.

Re: How to merge part of a dataset with another dataset

m1986MM — Thu, 27 Nov 2014 05:32:41 GMT

Thanks.