Updating Data in Existing Table

[maf9]

I'm new to sas so this is probably dumb question.  I have two tables, one is just a template that has every possibility.  The second is a subset of that template with the data filled in.  I want to merge the two so I keep all the rows but fill in the data where available.  Any ideas.

Table 1:

Key	C.1	C.2	C.3
A
B
C
D

Table 2:

Key	C.1	C.2	C.3
B	1	3	5
D	2	4	6

Output:

Key	C.1	C.2	C.3
A
B	1	3	5
C
D	2	4	6

[ballardw]

If your table 1 does not have duplicates of the Key variable and both table 1 and table 2 are sorted by the key then:

data newtable;
   update table1
          table2
   ;
   by key;
run;

Note that table2 can have multiple records with the same key variable(s) and all of the values will be used to update the single record in table1 with that Key.