Rolling 12 months oracle - sql

I am writing a query in Oracle that I want to automate. I currently have a where clause that has the following:
TRAN.DATE BETWEEN 20160101 AND 20161231
I want the query to be a 12 month look back from the current date. I think I can do it if the date was in a date format using the following:
TRAN.DATE BETWEEN ADD_MONTHS(SYSDATE, -12) AND SYSDATE
But the date format in the table is in an integer format. I have tried to the TO_DATE function but I can't get the format right.

Yikes, you mean your database table literally has an integer of 20170104 (twenty million, one hundred seventy thousand, one hundred and four) and this represents the forth of Jan, this year?
Setting aside any concerns I have about this not being the best way to store a date, it's probably going to be easiest to write and also understand, if you convert your date to char and then to int:
WHERE DATECOLUMN BETWEEN
TO_NUMBER(TO_CHAR(ADD_MONTHS(SYSDATE,-12),'YYYYMMDD')) AND
TO_NUMBER(TO_CHAR(SYSDATE,'YYYYMMDD'))
There's no point getting clever and trying to deal with it as an integer math problem by subtracting 1200 or 10000 etc as a number because it'll make your query hard to understand and have no performance gain at all over a couple of number conversions as per this way
You'd be better off changing those dates to actual dates right now, before the codebase grows any bigger and someone decides it's a good idea to add more date columns stored as ints

You could try
TO_DATE(TRAN.DATE, 'YYYYMMDD') BETWEEN ADD_MONTHS(SYSDATE, -12) AND SYSDATE

According to Oracle documentation,
TO_DATE converts char of CHAR, VARCHAR2, NCHAR, or NVARCHAR2
datatype to a value of DATE datatype
so you need to first cast integer column to char or any of the accepted datatype specified above, and then cast it to DATE as below.
SELECT TO_DATE(to_char(20160101),'YYYYMMDD') as DATE1 FROM DUAL
Result
DATE1
-------------------
01.01.2016 00:00:00
so you need to rewrite your query as below.
TO_DATE(to_char(TRAN.DATE),'YYYYMMDD') BETWEEN ADD_MONTHS(SYSDATE, -12) AND SYSDATE
Also if you need only date part, you amy also need to trunc sysdate.
You can check the demo here
Hope this will help.

Related

How I can convert date to char and then ti number?

Please help to sole this task. I need convert date to char and then to number, so that i can perform arithmetic operation and divide the date by 2.
select (sysdate+30+30+89)/2 from dual;
This query doesn't work and i have no idea how i can convert date to number.
The only sensible reason that I can think of for doing something like this is to get the midpoint of two dates, where one is sysdate.
If that is what you are trying to do, subtract the dates and divide by 2. Dividing an interval in half makes sense. Then add the resulting interval back to one of the dates.
For instance:
select date '2020-01-01' + (sysdate - date '2020-01-01') / 2
from dual
Based on the understanding of the question I think you need the current day of the year to perform arithmetic operation
SELECT (to_number(to_char(sysdate,'DDD'))+30+30+89)/2 from dual;

How to transform Oracle DateTime to Date

For instance, I have a datetime like this '2016-04-02 00:00:00' and another like this '2016-04-02 15:10:00'. I don't care about the time-part, I want them to match just by the date-part.
I have tried with date(), to_date, datepart, nothing works.
Do it like this:
where yourField >= the start of your date range
and yourField < the day after the end of your date range
Edit starts here:
While you could use trunc, as suggested by others, bear in mind that filtering on function results tends to be slow.
Truncating the date to day should do the trick. Documentation here:
https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions201.htm
For example
SELECT TRUNC(SYSDATE, 'DAY') FROM DUAL;
As others have said - there is no separate "date" data type in Oracle. A pure "date" is stored as a date with the time portion set to 00:00:00 (midnight at the beginning of the day), and TRUNC(date) will take any date and truncate the time to 00:00:00, so if you need to compare two dates you can write
where trunc(date_1) = trunc(date_2)
If your tables are very large and you need to do these comparisons often, this is not ideal, because wrapping column values within function calls (like date_1 within a TRUNC) prevents the use of an index you may have on the date_1 column. If you need to compare dates in two columns you may not have much of a choice, but if you compare to a fixed date (or something like SYSDATE) you may be better off with something like
where date_1 >= trunc(sysdate) and date_1 < trunc(sysdate) + 1
Here you are not using trunc on the column value, so if there's an index on the column, Oracle is free to use it - and trunc(sysdate) is computed only once, not for every single row. "+1" by the way means "add one day".
TO_DATE converts a string to a date; if you apply TO_DATE to a value that is already a legitimate date, you will get unexpected results because Oracle will first convert your true date to a string and then back to date again, and since these conversions require a date FORMAT for strings, and the formats Oracle assumes for conversion from date to string and from string to date may not match, .... you get the idea. As far as I know, DATE() (a FUNCTION) and DATEPART do not exist in Oracle; when you use a new language, keep Google close by and use it often.
If you input a date with no time component, for example TO_DATE('04-apr-2016, 'dd-mon-yyyy'), then the implicit time is 00:00:00 so you don't need to apply TRUNC() to it.
Good luck!

Sysdate Oracle to Run Based on Day

This is probably an easy question for most of you but how can I get this mask to run based on just the day?
If anyone knows Crystal Reports syntax, we have this and it works {PO_RECEIPTS.DATE_RECEIVED} = currentdate
However, when converting to Oracle SQL, how can I the standard: TO_CHAR
(SYSDATE, 'MM-DD-YYYY HH24:MI:SS') to become range so we can selected everything during the day, not just what matched the second in which the report was ran which it never will.
So something like Today from 00:00:00 to 23:59:59 ?
Thank you!
If PO_RECEIPTS.DATE_RECEIVED is a date column where all the times are set to midnight then you can do:
WHERE PO_RECEIPTS.DATE_RECEIVED = TRUNC(sysdate)
If the values have other times then you can use a range:
WHERE PO_RECEIPTS.DATE_RECEIVED >= TRUNC(sysdate)
AND PO_RECEIPTS.DATE_RECEIVED < TRUNC(sysdate) + 1
Truncating a date sets the time to midnight, by default, so TRUNC(sysdate) is midnight this morning. For the range you get all records equal to or later than midnight this morning, and less than midnight tomorrow - which is what TRUNC(sysdate) + 1 gives you, using normal Oracle datetime arithmetic.
You don't really want to convert it to a string with TO_CHAR(); you'd either have to convert all the column values to strings too (which is inefficient and prevents an index being used), or let the string be (implicitly) converted back to a date anyway. It's better to compare a column value with the same data type to reduce or avoid confusion.

Issue with date formatting SQL

SELECT LISTING_EOD.LOCATION, LISTING_EOD.APPTTIME, LISTING_EOD.PERSON_ID,
LISTING_EOD.FORENAME, LISTING_EOD.SURNAME, LISTING_EODS.STATUS,
LISTING_EOD.DBDATE
FROM DBNAME.LISTING_EOD LISTING_EOD;
This query returns a list of data processed today, I need to modify to check yesterday's data. I have tried add the below line of code, but it doesn't return anything. Does anyone know how I can achieve this?
where LISTING_EOD.DBDATE = '18-OCT-2012';
If you always want yesterday's data, rather than hard-coding the date you can use:
WHERE LISTING_EOD.DBDATE >= TRUNC(SYSDATE) - 1
AND LISTING_EOD.DBDATE < TRUNC(SYSDATE)
TRUNC(SYSDATE) gives you midnight this morning, so if run today it would give a range between 18-Oct-2010 00:00:00 and 18-Oct-2012 23:59:59.
It's generally not a good idea to use implicit date format masks; your original code assumes your NLS_DATE_FORMAT is set to DD-MON-YYYY, but that might not be correct now (if you're seeing the time in the existing select then it probably isn't), and may well not be in the future. Always use an explicit date format mask, like TO_DATE('18-OCT-2012', 'DD-MON-YYY'), to avoid ambiguity and unexpected behaviour.
If the field is actually VARCHAR2 rather than a DATE - which is bad - then you'll need to convert the date range to a string to get a match:
WHERE LISTING_EOD.DBDATE >= TO_CHAR(TRUNC(SYSDATE) - INTERVAL '1' DAY, 'DD-MON-YYYY HH24:MI:SS')
AND LISTING_EOD.DBDATE <= TO_CHAR(TRUNC(SYSDATE) - INTERVAL '1' SECOND, 'DD-MON-YYYY HH24:MI:SS')
That will work for a single day, just, but you'd have problems looking for a date range. It's much better and safer to store data in a column of the appropriate type.
Dates in Oracle by default contain time as well. If you just specify '18-OCT-2012', it will only match 18-OCT-2012 00:00:00'. One way to get around this is to format your database date to what you are comparing it to, e.g. to_char(LISTING_EOD.DBDATE, 'DD-MON-YYYY') and compare this to '18-OCT-2012'. This comparison will disregard time completely.
If you had a date variable to compare with instead of a string, format this using the same date mask used for the database date. This also gets around any assumptions abut default date format on the database in question.
I realised the 'table' I was querying was a view, examined it inside sqldeveloper, and added '-1' to the sysdate. This query then returned the previous days results.
I successfully retrieved the correct data, thanks for all help received.

Oracle to_date function with quarter-format

I need to find some records created in a range of quarters. For example, I'm looking for all records created between the 4th quarter of 2008 and the 1st quarter of 2010. I have this in my WHERE-clause:
...and r.record_create_date between to_date('2008 4','YYYY Q')
and to_date('2010 1','YYYY Q')
but Oracle says: ORA-01820: format code cannot appear in date input format. The Q is a valid date format symbol, so I'm not sure what's happened. Is this even a valid way to find values in between calender quarters, or is there a better way?
Also interesting, and possibly related, if I execute this:
select to_date('2009','YYYY') from dual;
The value displayed in my IDE is 2009-08-01. I would have expected 2009-08-04, since today is 2010-08-04.
This:
select to_date('2009 1','YYYY Q') from dual;
of course, fails.
(Oracle 10g)
Oracle says: ORA-01820: format code cannot appear in date input format. The Q is a valid date format symbol, so I'm not sure what's happened.
See the second column of table 2.15 at http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/sql_elements004.htm#i34948. Not all format elements are allowed when converting to dates, timestamps, etc.
I recommend against using between for date range checks. People often will miss values within the ending day that the expect to be included. So I would translate:
and r.record_create_date between to_date('2008 4','YYYY Q')
and to_date('2010 1','YYYY Q')
To
and to_date('2008-10-01', 'YYYY-MM-DD') <= r.record_create_date
and record_create_date < to_date('2010-04-01', 'YYYY-MM-DD') -- < beginning of 2Q2010.
Someone asked the same question on OTN: http://forums.oracle.com/forums/thread.jspa?threadID=1081398&tstart=255
The crux of the issue is that you can not specify "Q" in the TO_DATE function.
Given that you're already specifying a portion of the date, why not provide the entire date? Mind too that to_date('2010 1','YYYY Q') would give you Jan 1st, 2010 when you really want March 31st, 2010... at a second to midnight.
Since the relationship between quarters to months is one-to-many, it doesn't make sense to do TO_DATE('2008 1', 'yyyy q'); what date should be returned? The first of the quarter, the end of the quarter, ...? (On the other hand, converting a date to a quarter - like TO_CHAR(SYSDATE, 'yyyy q') makes sense because a specific date only exists in one quarter.)
So, if you do want a query that looks for a date that falls between two quarters, you will have to "rolll your own" (explicitly stating the dates of the start/end of a quarter.)
As a side note, in case anyone is considering not using TO_DATE please do not use things like: WHERE date_value BETWEEN 'date string1' and 'date string2' without the TO_DATE function. It assumes a default date format and under certain situations can avoid potentially useful indexes altogether.
Below is one example where the same query can have a different result.
select sysdate from dual where sysdate between '1-Jan-10' and '31-Dec-10';
SYSDATE
---------
04-AUG-10
SQL> alter session set nls_date_format = 'YYYY-MM-DD';
Session altered.
SQL> select * from dual where sysdate between '1-Jan-10' and '31-Dec-10';
no rows selected
(Notice that in the second instance no error is returned. It just assumes Jan 10, 0001 and Dec. 10th, 0031.)
I think the best way is to just input the quarter start date and quarter end dates without even bothering with to_date. I think if you use
between '1-Jan-10' and '31-Dec-10'
for example, then you don't (in Oracle I believe) need to_date and it isn't much more difficult than typing in the quarter number
To calculate in Oracle the first day of a quarter and the last day of a quarter from the year and quarter:
I Use the fact
start_month= -2 + 3 * quarter
last_month = 3 * quarter
variable v_year number
variable v_quarter number
exec :v_year :=2017
exec :v_quarter:=4
select :v_year as year,
:v_quarter as quarter,
to_date(:v_year||to_char(-2+3*:v_quarter,'fm00'),'yyyymm') as quarter_start,
last_day(to_date(:v_year||to_char(3*:v_quarter,'fm00')||'01 23:59:59','yyyymmdd hh24:mi:ss')) as quarter_end
from dual a;
YEAR|QUARTER|QUARTER_START |QUARTER_END
2017| 4|2017-10-01 00:00:00|2017-12-31 23:59:59