INVALID IDENTIFIER error in SEQUEL statement

Question

I'm having trouble with this SELECT statement in a report with search items. The search item in Question is the string "Email." Any activity record that has "Email" in the activity_type field is to be selected. The line of code is:
select user_name,total from (select user_name,count(*) total from eba_ver2_cust_activity where activity_type = Email group by user_name )
order by 2 desc,2 desc
There are some substitutions in here. The value "Email" is from :P23_ACTIVITY_TYPE on the page.
The error I get is:
failed to parse SQL query:
ORA-00904: "EMAIL": invalid identifier
The problem is that the String constant is being interpreted as an identifier name. Some sbustitutions are made to general the SELECT statement that fails. The relevant portion of the code generating the erroneous SELECT is:
if :P23_ACTIVITY_TYPE != '%null%' and :P23_ACTIVITY_TYPE is not null then
if :P23_START_DATE is not null or :P23_END_DATE is not null then
l_sql := l_sql || ' and activity_type_id = ' || :P23_ACTIVITY_TYPE ;
else
l_sql := l_sql || ' where activity_type_id = ' || :P23_ACTIVITY_TYPE ;
end if;
Either way, the contents of :P23_ACTIVITY_TYPE are treated as an identifier instead of a string. Please help.
Steve "the n00b" in Raleigh NC

Answer 1

Hi, Aaron.
I tried what you said, and my code wouldn't parse correctly. Let me show you the whole module of PL/SQL that I'm dealing with here. I did not write this. This is something I'm maintaining and updating. The part that chokes is near the bottom.
declare
l_sql varchar2(4000) := 'select user_name,total from (select user_name,count(*) total from eba_ver2_cust_activity ' ;
begin
if :P23_START_DATE is not null and :P23_END_DATE is not null then
l_sql := l_sql || ' where ACTIVITY_DATE between ''' || to_char(to_date(:P23_START_DATE,'dd-mon-yyyy'),'dd-mon-yyyy')
|| ''' and ' || '''' || to_char(to_date(:P23_END_DATE,'dd-mon-yyyy') ,'dd-mon-yyyy') || '''' ;
elsif :P23_START_DATE is not null then
l_sql := l_sql || ' where ACTIVITY_DATE >= ''' || to_char(to_date(:P23_START_DATE,'dd-mon-yyyy'),'dd-mon-yyyy') ||
elsif :P23_END_DATE is not null then
l_sql := l_sql || ' where ACTIVITY_DATE <= ''' || to_char(to_date(:P23_END_DATE,'dd-mon-yyyy'),'dd-mon-yyyy') || ''''
end if;
if :P23_ACTIVITY_TYPE != '%null%' and :P23_ACTIVITY_TYPE is not null then
if :P23_START_DATE is not null or :P23_END_DATE is not null then
l_sql := l_sql || ' and activity_type_id = ' || :P23_ACTIVITY_TYPE ;
else
l_sql := l_sql || ' where activity_type_id = ' || :P23_ACTIVITY_TYPE ;
end if;
end if;
l_sql := l_sql || ' group by user_name )' ;
return l_sql ;
end ;
I appreciate all the help. As for the job market for Apex programmers around here, I wouldn't know. I was a COBOL programmer for many years. I'm approaching retirement, and this will probably be my last IT job.
Steve "the n00b" in Raleigh NC