difference between Set and Marge statement, why output table is different

[mahossain]

/* Concatenate (or Union) the two data sets*/
data GroupA;
input ID$ Product$;
datalines;
A Apple
B Grapes
B Orange
C Banana
E Apple
run;

data GroupB;
input ID$ Product$ Size$;
datalines;
B Shirt S
C Pants M
D Jacket L
E Tie M
E Wallet L
run;

data concat;
set GroupA GroupB;
run;
proc sort data=concat;
by ID;
run;
/* Merge the two data sets*/
data merged;
merge GroupA GroupB;
by ID;
run;

[Reeza · Accepted solution]

SET appends data, ie stacks the datasets on top of each other.
MERGE adds data in a side to side fashion, making you data wider.

You SHOULD NOT be expecting the same results from the different code.

All the different options and methods are explained here:
https://documentation.sas.com/?docsetId=lrcon&docsetTarget=n1tgk0uanvisvon1r26lc036k0w7.htm&docsetVe...

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@mahossain wrote:

/* Concatenate (or Union) the two data sets*/
data GroupA;
input ID$ Product$;
datalines;
A Apple
B Grapes
B Orange
C Banana
E Apple
run;

data GroupB;
input ID$ Product$ Size$;
datalines;
B Shirt S
C Pants M
D Jacket L
E Tie M
E Wallet L
run;

data concat;
set GroupA GroupB;
run;
proc sort data=concat;
by ID;
run;
/* Merge the two data sets*/
data merged;
merge GroupA GroupB;
by ID;
run;

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