Question

My users want to be able to cut and paste a plain text email message into Application Express, and have the content of the email parsed and populate records in a table. The email messages are typically 10,000 – 20,000 characters, so I can put the email into a VARCHAR2 or a CLOB.

What I’m asking is for guidiance / pseudocode / hints for a way to parse these emails once I’ve populated the VARCHAR2 or the CLOB.

The messages have the following format:

Item One: content for item one

Item Two: 

multiline content for item two
more multiline content for item two

*********************************    <- these asterisks are in the text
Section Header I don't care about
*********************************

Item Three: content for item three

and so on.

The item headers are known in advance, and are in a constant and defined order.

I’d prefer to do this via PL/SQL as this will be implemented in the Oracle hosted Apex instance, but I believe Java can be used there as well (PL/SQL is much preferred).

Answer 1

The following code gives you an example of how to use instr and substr. All you need further is a way to put this code in a loop and populate l_header_first and l_header_next so you can get all the values you want.

declare
   l_email        varchar2(32767);
   l_first        pls_integer;
   l_next         pls_integer;
   l_text         varchar2(32767);
   l_header_first varchar2(100);
   l_header_next  varchar2(100);

begin
   l_email := 'Item One: content for item one

Item Two: 

multiline content for item two
more multiline content for item two

*********************************    <- these asterisks are in the text
Section Header I don''t care about
*********************************

Item Three: content for item three';

   l_header_first := 'Item One:';
   l_header_next  := 'Item Two:';
   l_first        := instr(l_email, l_header_first) + length(l_header_first) + 1;
   l_next         := instr(l_email, l_header_next);

   l_text := substr(l_email, l_first, l_next - l_first);
   dbms_output.put_line('Found ' || l_header_first);
   dbms_output.put_line(l_text);

   l_header_first := 'Item Two:';
   l_header_next  := 'Item Three:';
   l_first        := instr(l_email, l_header_first) + length(l_header_first) + 1;
   l_next         := instr(l_email, l_header_next);

   l_text := substr(l_email, l_first, l_next - l_first);
   dbms_output.put_line('Found ' || l_header_first);
   dbms_output.put_line(l_text);

end;