how to use vlookup equivalent in SAS for 2 datasets

[deep3]

Hi Please help my query.

I am using SAS studio. I have been trying to find a serial number match between two table and update the values of the numbers that match in a new column

Table1:

ser_no x1 x2..

Table2 

ser_num x3 x4..

If the ser_no from table1 is present in table 2 (ser_num column) then fill the same value in a new column 'Comparison' in Table 1.

This is equivalent to =VLOOKUP(G1,$J:$J,1,0) G is ser_no (table1) J is ser_num from table2

I tried creating the entire column of table 2 in a macro variable.But nothing seems to work.

data testing;
 if _n_ eq 1 then do;
  if 0 then set table2;
  declare hash h(dataset:'table2');
  h.definekey('x3','x4');
  h.definedata('ser_num');
  h.definedone();
 end;
set table1;

run;

[RW9]

Please show test data, in the form of a datastep.  It is not possible to diagnose a problem with a data based programming language without seeing data.  At a rough guess, I would just merge the two datasets together e.g.

data want;
  set have1 have2;
  by idvar;
  combined_var=coalsecec(varfromhave1,varfromhave2);
run;

There are a lot of assumptions in there, both sorted by idvar, both has idvar, etc.  Again, without seeing data I couldn't possibly guess what you have.