CASE statement... problem using it... what have I done to deserve this?

Question

I'm trying to use a CASE statement in Ora 8.1.7 (with compatible
set to 8.1.0) and am finding that I cannot compile the
procedure.
I'm using the CASE statement in a call to a procedure...
insert_addr (p_id_number => v_id_number,
p_addr_type => v_addr_type,
p_addr_status => v_addr_status,
p_addr_pref_ind => v_pref_addr_ind,
p_date_modified =>
(CASE
WHEN cmf_rec.hadoc = cnv_constants.nov17_1958
THEN cmf_rec.doe
ELSE cmf_rec.hadoc
END)
I'm getting "PLS-00103 Encountered the symbol "CASE" when
expecting one of the following..." error msg when compiling.
What have I done wrong? Syntax error? Should I change the
compatible parameter?
Thanks.

Answer 1

You can actually use the CASE statement in Pl/Sql, though not like in SqlPlus.
You have to use dynamic Sql.
Example
create or replace procedure test_case1 is
v_sql varchar2(4000);
begin
v_sql := 'update case_test set qual_rule = '||
         '(case '||
         ' when dob < ''01-jan-1902'' then ''100+'' '||
         ' when dob between ''01-jan-1902'' and ''31-dec-1912'' then ''90-99'' '||
         ' when dob between ''01-jan-1912'' and ''31-jan-1932'' then ''70-89'' '||
         ' when dob between ''01-jan-1932'' and ''31-jan-1952'' then ''50-69'' '||
         ' when dob between ''01-jan-1952'' and ''31-jan-1972'' then ''30-49'' '||
         ' when dob between ''01-jan-1972'' and ''31-jan-1984'' then ''< 30'' '||
         ' else ''under age'' '||
         ' end ) ';
execute immediate v_sql;
commit;
end test_case1;