Extract field error

Question

I have the following select to extract a date containing month and year from a varchar2 column
select to_char(sau_date,'MM') MONTH,extract(year from sau_date) YEAR, count(*) COUNT
from mac.sysaud
group by to_char(sau_date,'MM'),extract(year from sau_date)
order by extract(year from sau_date), to_char(sau_date,'MM');when running select i receive a ora-30076:invalid extract field for extract source

Answer 1

Hi,
user11978142 wrote:
varchar2 column date is displayed as
20071015
20071015
20061020
20061020
\{code}
i just wanted to extract the date
table contains millions of rows..so its a bit difficult to post dataThat's why you need to post sample data. Four rows might be enough.
If all you need is a count of rows for each month, then:
SELECT       SUBSTR (saud_date, 1, 6)     AS year_month
,       COUNT (*)                    AS cnt
FROM       sysaud
GROUP BY  SUBSTR (saud_date, 1, 6)     
ORDER BY  year_month
;If you need separate columns for month and year, call SUBSTR twice where I called it once.
This will be more efficient than using TO_DATE, and it not raise an error if there are invalid strings (such as month '00').
On this site, you have your choice of what kind of code tags to use. Whichever type you choose, be consistent.
If the opening tag uses square brackets, then the closing tag must use square brackets, too. With square brackets, the closing tag has a / , and capitalization doesn't matter. For example
[code]
SELECT    SUBSTR ...
[/code]If the opening tag uses curly brackets, then the closing tag must use curly brackets, too. With curly brackets, the closing tag is identical to the opening tag, without a / , and you can only use lower-case letters.
Edited by: Frank Kulash on Feb 12, 2011 3:26 PM