to_number substring remove zero at lefthands? - sql

Question

I have this string
abcd-0490-abcd
I am getting the number part using substr('abcd-0490-abcd',5,4) but the problem is that I want to increment that number by one so I add the to_number like that
to_number(substr('abcd-0490-abcd', 5,4 ))
which will remove the zero number at the left hand that's coz an error to my script so its not catching correct data i want
anyway to avoid this
create or replace procedure pro
(yy in varchar2 default '[0-9]{2}',mm in varchar2 default '[0-9]{2}') as pattern varchar2(80);
cursor cur (pattern varchar2) is
with t as
(
select
substr(column1, 5,4 ) as seq,
substr(column1, 10, 2) as yy,
substr(column1, 13, 2) as mm,
substr(column1, 16, 2) as dd
from test1
where regexp_like(column1, pattern)
),
r (yy, mm, dd, seq, max_seq) as (
select yy, mm, dd, min(seq), max(seq)
from t
group by yy, mm, dd
union all
select yy, mm, dd, seq + 1, max_seq
from r
where seq + 1 <= max_seq
)
select yy, mm, dd, seq as missing_seq
from r
where not exists (
select 1 from t
where t.yy = r.yy
and t.mm = r.mm
and t.dd = r.dd
and t.seq = r.seq
)
order by yy, mm, dd, seq;
begin
pattern := 'Cabcd[-][0-9]{4}[_][0-9]{2}'|| yy ||'[_][0-9]{2}' || mm || '[_][0-9]{2}[_][0-9]{4}[_][T]["2"]';
for rec in cur(pattern) loop
dbms_output.put_line(rec.missing_seq);
end loop;
dbms_output.put_line('Done');
end pro;
/

Answer 1

Use LPAD function:http://docs.oracle.com/cd/E11882_01/server.112/e26088/functions095.htm#SQLRF00663
select lpad( to_number(substr('abcd-0490-abcd', 6,4 )) + 1 , 4, '0')
from dual;
demo: http://sqlfiddle.com/#!4/d41d8/25730

Answer 2

The default number-to-character conversion does not produce leading zeros.
Do an explicit TO_CHAR to define your format:
SELECT TO_CHAR(490, 'FM0000') FROM dual;
0490
Edit: This is an example with your query.
SELECT TO_CHAR( TO_NUMBER( SUBSTR( 'abcd-0490-abcd', 6, 4 ) ) + 1, 'FM0000' )
FROM dual;
0491

Answer 3

better u try " rownum " for increment
SELECT TO_CHAR( TO_NUMBER( SUBSTR( 'abcd-0490-abcd', 6, 4 ) ) +rownum, 'FM0000' )
FROM dual;
use table dual instead of any other table in ur database.
SELECT TO_CHAR( TO_NUMBER( SUBSTR( 'abcd-0490-abcd', 6, 4 ) ) +rownum, 'FM0000' )
FROM 'your_tablename';