When merging two data sets by a variable why all OBS not populated with values

[knveraraju91]

Dear,

I have a question. 

I am merging two datasets. why only first OBS is populated in my output data.  Please help. Thank you

code:

data data3;
merge data2(in=a) data1(in=b);
by id;
if a;
run;

data1

id      value

1         10

2          20

3          30

data2

id 

1

1

2 

2

2

output getting;

id    val

1     10

1

2     20

2

2

output needed;

id    val

1     10

1      10

2     20

2      20

2     20

[LinusH]

Not thought about this consequence when using the if a; concept.
Not tested but my theory is that for observation 2 there is no corresponding observation in b: hence the missing value.
Regardless I think a simple SQL inner join is better in this situation.

[Shmuel]

I'm using SAS 9.4 with SAS UE on linux.

Attached is the code and result.

The code is a copy of your (@knveraraju91 ) post, addaptedf to create test data.

The result is as you wanted.

Check your log and code again. It should work.

If not - what SAS version and platform you use ?

[Kurt_Bremser]

Are you sure that data2 only contains the variable id?

Please post the output of proc contents for both datasets.

[Astounding]

The results you are getting would typically occur if your second data set also contained VAL (or is it VALUE?), but with all missing values.  To get rid of it, you can drop it as late as on the MERGE statement:

data want;

merge data2 (in=a drop=val) data1;

by id;

if a;

run;