Header and Trailer updating the same record

Question

Hi all
I have a requirement in SQL loader in which the header should go to a header_trailer table. ( only 5 out of 10 columns are updated by the header record).
All the data records go to a second table.( some xyz table)
The trailer record should again update the record inserted by the header record in header_trailer table(the remaining 5 columns)
How can I do this
Each record in the header_trailer record will be identified by a sequence which should be populated when the header inserts the record
Thanks
Ashwin N.

Answer 1

You're in luck, I'm a bit bored so I wrote a little script. This is just one way of doing it. It makes sure you can run this code in parallel as much as you want. However, you do get a lot of control and log files, but there is no escaping that. If the parallel option is not a requirement there are easier solutions (e.g. using a function called in the control file to fetch the last batch number from the lb_hf table). That way the control file can remain static.
I also experienced some problems with the nummeric value in a definition variable. I solved it by turning it into a char and later in a number again, but this must be simpler. Anyways, this works and should suffice for your learning purposes:
Create 2 files. One called 'l.dat' with the following data in it:
a,b
c,dThe other file called 'l.sql' with the following script in it:
-- script to test loading data in staging area and create/update header table
define usr=scott
define pwd=tiger
define db=oracle
whenever sqlerror exit
conn &usr/&pwd@&db
whenever sqlerror continue
create table lb_stage (-- this is the staging table in which the data will be loaded
  batch_num number,
  c1 varchar2(30),
  c2 varchar2(40));
create table lb_hf (--  this is the footer table
  batch_num number,
  load_start date,
  description varchar2(30),
  records_loaded number,
  load_end date);
create sequence lb_hf_seq;
set verify off
-- fetch new sequence for this particular load
col hf_seq_nr format a30 new_value v_hf_seq_nr
select to_char(lb_hf_seq.nextval) hf_seq_nr from dual;
-- create header record
insert into lb_hf values (to_number('&v_hf_seq_nr'), sysdate, 'Automated load', null, null);
commit;
-- create control file (needed to hardcode the sequence number in)
set feedback off
spool l_&v_hf_seq_nr..ctl
prompt load DATA
prompt INTO TABLE lb_stage
prompt FIELDS TERMINATED BY ';' OPTIONALLY ENCLOSED BY '"'
prompt TRAILING NULLCOLS
prompt (
prompt batch_num char "&v_hf_seq_nr",
prompt c1,
prompt c2
prompt )
spool off
set feedback on
-- load data (also have batchnum in log file name)
host sqlldr &usr./&pwd.@&db. data=l.dat control=l_&v_hf_seq_nr..ctl log=l_&v_hf_seq_nr..log
-- update header record with load information
update lb_hf set records_loaded = (select count(1) from lb_stage where batch_num = &v_hf_seq_nr), load_end = sysdate where batch_num = &v_hf_seq_nr;
commit;
select * from lb_stage;
select * from lb_hf;
drop table lb_stage;
drop table lb_hf;
drop sequence lb_hf_seq;
prompt End of script.Change the login at the beginning to something appropriate and run l.sql from the sql prompt.
Hope this helps,
Lennert