Select Month in Oracle Query - oracle

I tried the below query in oracle
select cast(TO_DATE (cal.MONTH,'MM') AS varchar2(30)) as result
FROM JOBCONTROL_USER.ods_calendar_weeks cal
WHERE cal.YEAR NOT IN (0, 9999)
it gives result in dd-mon-yy format. Now I want only mon from the result, how can I achieve this without using to_char()?

If you're avoiding Oracle functions and the month number is stored on its own as a varchar2 field, then you could brute-force it:
select case cast(month as number)
when 1 then 'Jan'
when 2 then 'Feb'
when 3 then 'Mar'
when 4 then 'Apr'
when 5 then 'May'
when 6 then 'Jun'
when 7 then 'Jul'
when 8 then 'Aug'
when 9 then 'Sep'
when 10 then 'Oct'
when 11 then 'Nov'
when 12 then 'Dec'
end as mon
from ods_calendar_weeks cal
where cal.year not in (0, 9999);
But you're having to specify the language; you don't get Oracle's conversion of the month to the NLS date language. Which might be a bonus or a problem depending on your context.
I'd be tempted to put the conversions into a look-up table instead and join to that; or to add the month name as a separate column on the table, as a virtual column in 11g.

You can try somthing like this:-
SELECT EXTRACT(MONTH FROM CAST(TO_DATE (cal.MONTH,'MM') AS varchar2(30))) as RESULT
FROM JOBCONTROL_USER.ods_calendar_weeks cal
WHERE cal.YEAR NOT IN (0, 9999)
Hope this will help you.

select to_char(cal.Month,'month')
) AS result
FROM JOBCONTROL_USER.ods_calendar_weeks cal
WHERE cal.YEAR NOT IN (0, 9999);
This will gives month. the to_char() is a function which has two arguments 1. Column name ans 2. Month. Column name is of date data type so we have to convert the date into character data type and we required only the month so the second column will describes what will be extracted from the date. Finally the result is displayed as a character datatype. This query will returns the months name if year neither 0 nor 9999.

Related

Oracle SQL Developer get table rows older than n months

In Oracle SQL Developer, I have a table called t1 who have two columns col1 defined as NUMBER(19,0) and col2 defined as TIMESTAMP(3).
I have these rows
col1 col2
1 03/01/22 12:00:00,000000000
2 03/01/22 13:00:00,000000000
3 26/11/21 10:27:11,750000000
4 26/11/21 10:27:59,606000000
5 16/12/21 11:47:04,105000000
6 16/12/21 12:29:27,101000000
My sysdate looks like this:
select sysdate from dual;
SYSDATE
03/03/22
I want to create a stored procedure (SP) which will delete rows older than 2 months and displayed message n rows are deleted
But when i execute this statement
select * from t1 where to_date(TRUNC(col2), 'DD/MM/YY') < add_months(sysdate, -2);
I don't get the first 2 rows of my t1 table. I get more than 2 rows
1 03/01/22 12:00:00,000000000
2 03/01/22 13:00:00,000000000
How can i get these rows and deleted it please ?
In Oracle, a DATE data type is a binary data type consisting of 7 bytes (century, year-of-century, month, day, hour, minute and second). It ALWAYS has all of those components and it is NEVER stored with a particular formatting (such as DD/MM/RR).
Your client application (i.e. SQL Developer) may choose to DISPLAY the binary DATE value in a human readable manner by formatting it as DD/MM/RR but that is a function of the client application you are using and not the database.
When you show the entire value:
SELECT TO_CHAR(ADD_MONTHS(sysdate, -2), 'YYYY-MM-DD HH24:MI:SS') AS dt FROM DUAL;
Then it outputs (depending on time zone):
DT
2022-01-03 10:11:28
If you compare that to your values then you can see that 2022-01-03 12:00:00 is not "more than 2 months ago" so it will not be matched.
What you appear to want is not "more than 2 months ago" but "equal to or more than 2 months, ignoring the time component, ago"; which you can get using:
SELECT *
FROM t1
WHERE col2 < add_months(TRUNC(sysdate), -2) + INTERVAL '1' DAY;
or
SELECT *
FROM t1
WHERE TRUNC(col2) <= add_months(TRUNC(sysdate), -2);
(Note: the first query would use an index on col2 but the second query would not; it would require a function-based index on TRUNC(col2) instead.)
Also, don't use TO_DATE on a column that is already a DATE or TIMESTAMP data type. TO_DATE takes a string as the first argument and not a DATE or TIMESTAMP so Oracle will perform an implicit conversion using TO_CHAR and if the format models do not match then you will introduce errors (and since any user can set their own date format in their session parameters at any time then you may get errors for one user that are not present for other users and is very hard to debug).
db<>fiddle here
Perhaps just:
select *
from t1
where col2 < add_months(sysdate, -2);

Single Month Digit Date Format issue in Oracle

Am getting the below issue when am using 'mon-d-yyyy' to convert date to char, as i need a single day digit for values from 1 to 9 days in a month.
When i use the 'mon-d-yyyy' format, am losing out on 5 days and getting a wrong date. Any help on this would be great.
select to_char(sysdate-22,'mon-d-yyyy') from dual;--aug-2-2017
select to_char(sysdate-22,'mon-dd-yyyy') from dual;--aug-07-2017
select sysdate-22 from dual;--07-AUG-17 11.06.43
In Oracle date formats, d gets the day of week. The 2 in your output means monday, not august the 2nd.
Try using Fill Mode as Format Model Modifier
select to_char(sysdate-22,'mon-fmdd-yyyy') from dual;
One option might be to piece together the date output you want:
SELECT
TO_CHAR(sysdate-22, 'mon-') ||
TRIM(LEADING '0' FROM TO_CHAR(sysdate-22, 'dd-')) ||
TO_CHAR(sysdate-22, 'yyyy')
FROM dual;
The middle term involving TRIM strips off the leading zeroes, if present, from the date.
Output:
Demo here:
Rextester
SQL>SELECT TO_CHAR(TO_DATE('29-AUG-2017','DD-MON-YYYY') - 22,'"WEEKDAY :"D, MON-FMDD-YYYY') "Before22Days" FROM DUAL;
D- Gives you a numeric weekday(2nd weekday in a week) on AUG-07-2017.
DD-Gives a Numeric Month Day i.e,07th
FMDD-Gives 7th
Before22Days
----------------------
WEEKDAY :2, AUG-7-2017

Oracle DB: calculate age from strings

I need to calculate age for the people and their birthdates are saved in varchar2 like 19900130, and some people don't have their birthdates recorded and default value is 00000000.
Here is my code:
SELECT
e.id_number,
e.birth_dt,
(CASE WHEN SUBSTR(e.birth_dt, 1, 4) = '0000' THEN 0
WHEN SUBSTR(e.birth_dt, 1, 4) <> '0000' THEN
ROUND(MONTHS_BETWEEN(SYSDATE, TO_DATE(e.birth_dt, 'YYYYMMDD')) / 12)
ELSE -1
END) age
FROM employee e
The error is:
ORA-01843: Not a valid month
Is anything wrong? I couldn't figure out.
Is anything wrong? Yes, your case is not covering the possibility that some strings have something other than 01, 02, ..., 12 in character positions 5 and 6. Likewise, your case is not covering the possibility that the day of the month character positions are something other than 01, 02, ... 31 (and the covering of the possibility that a day of the month is not valid for a particular month).
If I were you, I'd add a proper date column, modify the app to populate both columns, fix the app so that it stops putting bad data into the table, decide what to do with the bad data, modify the app to stop populating the varchar2 column, and then drop the varchar2 column.

Oracle SQL To compare 1 or 2 or more dates to be within a given period

I have a scenario where I need to compare 2 or more dates for given period.
I'm able to succeed when comparing 1 date to a period using between function. But challenge is when I have 2 dates to compare in parallel, getting single row sub query error
select A
from ORDER
where Date1 between sysdate and (sysdate-10)
Above query works fine for single date, please help to get a solution when I have Date 1 and Date 2 and need to compare against the same period (sysdate and (sysdate-10)) and I may have more than 2 dates as well.
Thanks
Shankar
Not having a proper description of your tables or the data they contain, it is difficult to know what you want.
Perhaps something like:
SELECT A
FROM ORDER
GROUP BY A
HAVING COUNT( CASE WHEN datecolumn BETWEEN SYSDATE - 10 AND SYSDATE THEN 1 ELSE NULL END ) > 0

Oracle - Date substraction in where clause

I'm trying to figure out how to compare the result of a date substraction in a where clause.
Clients subscribed to a service and therefore are linked to a subscription that has an end date. I want to display the list of subscriptions that will come to an end within the next 2 weeks.
I did not designed the databse but noticed that the End_Date column type is a varchar and not a date.. I can't change that.
My problem is the following:
If I try to select the result of the substraction for example with this request:
SELECT(TO_DATE(s.end_date,'YYYY-MM-DD') - TRUNC(SYSDATE)) , s.name
from SUBSCRIPTION s WHERE s.id_acces = 15
This will work and give me the number of days between the end of the subscription and the current date.
BUT now, if I try to include the exact same request in a clause where for comparison:
SELECT s.name
from SUBSCRIPTION S
WHERE (TO_DATE(s.end_date,'YYYY-MM-DD') - TRUNC(SYSDATE)) between 0 and 16
I will get an error: "ORA-01839 : date not valid for month specified".
Any help would be appreciated..
Somewhere in the table you have your date formatted in a different way from YYYY-MM-DD. In your first query you check a certain row (or a set of rows, s.id_acces = 15), which is probably ok, but in the second you scan through all the table.
Try finding these rows with something like,
select end_date from subscription
where not regexp_like(end_date, '[0-9]{4}-[0-9]{2}-[0-9]{2}')
Check your DD value (ie: day of the month). This value must be between 1 and the number of days in the month.
January - 1 to 31
February - 1 to 28 (1 to 29, if a leap year)
March - 1 to 31
April - 1 to 30
May - 1 to 31
June - 1 to 30
July - 1 to 31
August - 1 to 31
September - 1 to 30
October - 1 to 31
November - 1 to 30
December - 1 to 31
" the End_Date column type is a varchar and not a date.. I can't
change that."
If you can't change the date you'll have to chang3 the data. You can identify the rogue values with this function:
create or replace check_date_format (p_str in varchar2) return varchar2
is
d date;
begin
d := to_date(p_str,'YYYY-MM-DD');
return 'VALID';
exception
when others then
return 'INVALID';
end;
You can use this function in a query:
select sid, end_date
from SUBSCRIPTION
where check_date_format(end_date) != 'VALID';
Your choices are:
fix the data so all the dates are in the same format
fix the data and apply a check constraint to enforce future validity
write a bespoke MY_TO_DATE() function which takes a string and applies lots of different date format masks to it in the hope of getting a successful conversion.

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