Merging question?

Mirisage — Mon, 01 Apr 2013 14:35:47 GMT

Hi SAS Community,

I have two data files, cops and COL.

Data cops;

Input transit acctnum;

Cards;

1 111

1 222

1 333

;

Run;

Data COL;

Input transit acctnum;

Cards;

1 111

9 999

;

Run;

I need to identify what are the records in COL file that are not found in COPS file.

My approach:

I have done merging like below with the condition highlighted in green.

Proc sort data=cops out=t1;

by transit acctnum;

run;

proc sort data=col out=t2;

by transit acctnum;

run;

data t3 ;

merge t1 (in=a)

t2 (in=b)

;

by Transit acctnum;

if b and not a;

run;

This is the answer which is correct.

999

Question:

I have tweaked the merging condition as shown in yellow. This still gives the correct answer.

Could any merging expert confirm whether green and yellow conditions both essentially do the same.

I am asking this because the answer may be “yes” for this small data set but when I apply to my larger dataset, SAS may do

something else which I cannot detect.

data t4 ;

merge t1 (in=a)

t2 (in=b)

;

by Transit acctnum;

if not a ;

run;

Thank you for your help

Mirisage

Re: Merging question?

Reeza — Mon, 01 Apr 2013 14:52:53 GMT

It's the same as long as you have 2 datasets your merging. If you have 3 or more it won't be.

Re: Merging question?

Tom — Mon, 01 Apr 2013 14:54:05 GMT

If you just think about it as a logic problem then only values that would by in (B and NOT A) and not in (NOT A) are those with NOT B and NOT A. But that is impossible as the data has to come from somewhere.

topic Re: Merging question? in SAS Procedures

Merging question?

Re: Merging question?

Re: Merging question?