SQL script(column statement) understanding

Question

hi,
i am ataching the code of one of the SQL scripts. I am having problem in understanding some of the lines of the code for which i have put a comment, the lines start with the "column" statement and the spool statements. Please help in solving my query.
regards,
jatin
SET LINESIZE 200
SET PAGESIZE 10000
--Problem in understanding below 4 lines
column spool_text_source new_value spool_text
select 'c:\temp\DAR_' || to_char(sysdate,'YYYYMMDD')
spool_text_source from dual;
spool &spool_text..txt
--query starts here 
SELECT DISTINCT E.CITY_CODE,A.MOBILE_NO,A.ITEM_TYPE_ID,B.DOCUMENT_NUM,B.DOCUMENT_DT,E.DISTRIBUTOR_NAME
FROM
INV_SIM_SERIAL A,INVOICE_HEADER B,INVOICE_DETAIL C,INV_SIM_SERIAL D,DISTRIBUTOR_MASTER E WHERE
A.DOC_LINE_ID=C.DOC_LINE_ID AND
B.DOCUMENT_NUM=C.DOCUMENT_NUM AND
A.SERIAL_ID=NVL(D.OLD_SERIAL_ID,D.SERIAL_ID) AND
(trunc(A.FIRST_CALL_DT) = trunc(sysdate-1) OR trunc(D.FIRST_CALL_DT)= trunc(sysdate-1)) AND
NVL(A.OLD_DISTRIBUTOR_ID,A.DISTRIBUTOR_ID)=E.DISTRIBUTOR_ID AND A.ACTIVATE_DT IS NULL
order by e.distributor_name;
--query ends here
spool off
exit

Answer 1

Hi
The part
column spool_text_source new_value spool_text
select 'c:\temp\DAR_' || to_char(sysdate,'YYYYMMDD')
spool_text_source from dual;
spool &spool_text..txt can be written as
column spool_text_source new_value spool_text
select 'c:\temp\DAR_' || to_char(sysdate,'YYYYMMDD') spool_text_source from dual;
spool &spool_text..txt line 2 and 3 are just one sql-statement
but back to what it does
line 1 column ...
it tells SQL*Plus to get the result from the column spool_test_source of next sql-statement and put into the spool_text variable.
line 2 the SQL-statment it actuallt create an file name for the spool file and the result is put into the spool_text variable.
line 3 open the spool file and start spooling output from the script.