SAS哈希表中的动态.defineKey语句

Question

I am trying to dynamically specify a key for a hashtable. The below example works fine, and you can see I'm specifying the key via the key_list variable:

data ht;

  set sashelp.class;

  key_list = 'name';

  if _n_ eq 1 then do;
    declare hash ht(dataset:"sashelp.class");
    ht.defineKey(key_list);
    ht.defineDone();
  end;

  rc = ht.find();

run;

But the below change:

key_list = 'name,sex';

... produces the warning:

ERROR: Undeclared key symbol name,sex for hash object at line 6144 column 9.
ERROR: DATA STEP Component Object failure.  Aborted during the EXECUTION phase.

I've tried all the combinations of single/double quotes, spaces vs commas etc, to get this working without any luck. Has anyone been able to do this before?

I'm looking for a non-macro solution, thanks.

Answer 1

The keylist would always have columns quoted and separated by comma. So looking at what you are trying to do, i think trying to do a similar thing and by quoting the entire string and later when definekey is used we could use dequote function to remove the quotation mark applied to the entire string should help. Below is the change that i believe should help.

data ht;
  set sashelp.class;
  key_list =  "'name','sex'" ;
  if _n_ eq 1 then do;
    declare hash ht(dataset:"sashelp.class");
    ht.defineKey(dequote(key_list));
    ht.defineDone();
  end;
  rc = ht.find();
run;

I haven't tested it yet, let me know if it helps.