update target table with another source table using partial variables

[CHL0320]

Hi,

I would like to learn how to update a target table with values from another table. There are about 1000 variables in the target table and only about 350 variables (chat or num variables) need to be updated from a renew dataset. The rules are

1. If the renew dataset has value in the variables then use that value in the target dataset.
2. If the renew dataset has missing value then keep the value in the target dataset.
3. If both target and renew datasets have missing value then keep the value as missing. 

I have generated a very simple example.

data target;
input id1$ id2 a b c$ d$ e f;
datalines;
1 10 6 8 x1 x2 9 3
2 20 5 . y1 . 6 .
;
run;

data renew;
input id1$ id2 a b c$ d$ e f;
datalines;
1 . 6 8 x10 . 9 30
2 20 . 3 . y20 6 .
;
run;

the data want will be

id1	id2	a	b	c	d	e	f
1	10	6	8	x10	x2	9	30
2	20	5	3	y1	y20	6	.

Thank you so much.

[r_behata · Accepted solution]

data target;
	update target renew;
	by id1;
run;

Update Statement will meet your requirements :

1. It Does not update the value in the master by default, if the transaction table has missing values.

2. Sets to missing if both master and transaction have missing values