Sequence Operator

Question

How can I use Sequence Operator within a single mapping ???
I get a single value with Sequence.NextVal. Then, I need to use this value for further operations in the same mapping. For example: use value to update target table(s), pass the value to Post-Mapping Operator, pass the same value to Mapping-Output Operator and so on.
Thanks in advance

Answer 1

If all there is on the mapping is a sequence and a table, it looks as if he wants to use a single sequence value to either insert a single row to the table, or update the table with a single sequence nextval.
This is a valid task, but not really the sort of bulk inserts/updates that mappings are designed to do.
Assuming that I am correct, what I would suggest in this case, is replace the sequence with a constant of type number and set it's initial value via it's expression property to the sequence nextval. I would suggest making a database function such as:
CREATE OR REPLACE FUNCTION get_next_sequence_number_fnc (sequence_name in varchar2)
RETURN NUMBER PARALLEL_ENABLE
IS
retval number := null;
BEGIN
-- Sequence nextval wrapper to overcome SQL limitations on nextval
execute immediate 'select '||sequence_name||'.nextval from dual' into retval;
return retval;
END;
to do this task, so the Constant would get instatiated with an expression of get_next_sequence_number_fnc('your_sequence_name')
I haven't worked a major project yet that didn't need to use a get_next_sequence_number_fnc function to be able to access a sequence in a normally disallowed part of a complex query, so it's a handy function to keep around.
This will iterate once in the generated package specification, and then you could pass that variable value to both the table and post-mapping procedure without any problems.
Mike
Edited by: zeppo on Sep 5, 2008 9:03 AM, stuoid editer reformatting....