Oracle: TIMESTAMP data type - oracle

i am using timestamp for a field to store date and time, however when i fetch the rows from the table i get loads of zeros in the timestamp field.
SQL> select * from booking_session;
BK_ID|BK_DATE
----------|-------------------------
1|18-MAR-12 10.00.00.000000
2|18-MAR-12 10.25.00.000000
3|18-MAR-12 10.30.00.000000
4|18-MAR-12 10.35.00.000000
5|18-MAR-12 10.40.00.000000
The following is the insert statement
INSERT INTO BOOKING_SESSION VALUES (1,TO_TIMESTAMP('18/03/2012 10:00',
'DD/MM/YYYY HH24:MI')
Can someone please tell me how can the bk_date format be stored like 18-MAR-12 10.00 or at least have AM or PM next to it.
Thanks in advance.

You can declare BK_DATE column as timestamp(precision) where precision is a number of decimal digits to store fraction of a second. So you might have declared BK_DATE timestamp(0). If you do not need track time down to a fraction of a second use date data type to store dates. In any case time part (hh:mi:ss) will be there and if you insert data as you did, specifying only hour and minutes, then seconds will be fill in with zeros. You can use to_char function and appropriate date format mask to get rid of those trailing zeros at display time:
-- sample of data
SQL> with t1(BK_ID, BK_DATE) as(
2 select 1, to_timestamp('18-MAR-12 10.00.00.000000', 'DD-MON-RR HH:MI:SSxFF6') from dual union all
3 select 2, to_timestamp('18-MAR-12 10.25.00.000000', 'DD-MON-RR HH:MI:SSxFF6') from dual union all
4 select 3, to_timestamp('18-MAR-12 10.30.00.000000', 'DD-MON-RR HH:MI:SSxFF6') from dual union all
5 select 4, to_timestamp('18-MAR-12 10.35.00.000000', 'DD-MON-RR HH:MI:SSxFF6') from dual union all
6 select 5, to_timestamp('18-MAR-12 10.40.00.000000', 'DD-MON-RR HH:MI:SSxFF6') from dual
7 )
8 select bk_id
9 , to_char(bk_date, 'DD-MON-RR HH:MI') bk_date
10 from t1
11 ;
BK_ID BK_DATE
---------- ------------------------
1 18-MAR-12 10:00
2 18-MAR-12 10:25
3 18-MAR-12 10:30
4 18-MAR-12 10:35
5 18-MAR-12 10:40

Try the following query:
select * from booking_session where trunc(bk_date) = to_date('18-03-2012', 'dd-mm-yyyy');

Related

How to select the first 5 dates from each group and put them in a single column separated by comma in Oracle?

I have a table like this:
Division
Region
Date of Last Visit
1
2
11/20/2021
1
2
11/18/2021
1
7
10/18/2021
1
7
11/19/2021
2
2
11/17/2021
2
3
09/20/2021
2
3
10/20/2021
I want to write a query that groups by the division and region columns and gives me the last 5 dates for each group separated by commas in a single column. Something like this:
Division
Region
Date of Last Visit
Today
Days since last visit
1
2
11/20/2021, 11/18/2021
sysdate
sysdate - max(date of last visit)
1
7
10/18/2021, 11/19/2021
sysdate
sysdate - max(date of last visit)
2
2
11/17/2021
sysdate
sysdate - max(date of last visit)
2
3
9/20/2021, 10/20/2021
sysdate
sysdate - max(date of last visit)
The last two columns are custom calculated columns that I also need for the final output table. Any help would be greatly appreciated as I have tried a lot of things but I keep getting errors about it not being grouped properly, possibly because of the two extra columns at the end. But even without that, I am not sure how to fetch only the last 5 dates per group in oracle.
Thanks!
You want to filter the greatest-n-per-group using the ROW_NUMBER analytic function and then aggregate:
SELECT division,
region,
LISTAGG(TO_CHAR(date_of_last_visit, 'DD/MM/YYYY'), ',')
WITHIN GROUP (ORDER BY date_of_last_visit DESC)
AS date_of_last_visit,
SYSDATE AS today,
TRUNC(SYSDATE - MAX(date_of_last_visit)) AS days_since_last_visit
FROM (
SELECT t.*,
ROW_NUMBER() OVER (PARTITION BY division, region
ORDER BY date_of_last_visit DESC) AS rn
FROM table_name t
)
WHERE rn <= 5
GROUP BY
division,
region
Which, for the sample data:
CREATE TABLE table_name (division, region, date_of_last_visit) as
select 1, 2, date '2021-11-20' from dual union all
select 1, 2, date '2021-11-18' from dual union all
select 1, 7, date '2021-10-18' from dual union all
select 1, 7, date '2021-11-19' from dual union all
select 2, 2, date '2021-11-17' from dual union all
select 2, 3, date '2021-09-20' from dual union all
select 2, 3, date '2021-10-20' from dual;
Outputs:
DIVISION
REGION
DATE_OF_LAST_VISIT
TODAY
DAYS_SINCE_LAST_VISIT
1
2
20/11/2021,18/11/2021
30-NOV-21
10
1
7
19/11/2021,18/10/2021
30-NOV-21
11
2
2
17/11/2021
30-NOV-21
13
2
3
20/10/2021,20/09/2021
30-NOV-21
41
db<>fiddle here
Here you go; read comments within code.
SQL> with test (division, region, datum) as
2 -- sample data
3 (select 1, 2, date '2021-11-20' from dual union all
4 select 1, 2, date '2021-11-18' from dual union all
5 select 1, 7, date '2021-10-18' from dual union all
6 select 1, 7, date '2021-11-19' from dual union all
7 select 2, 2, date '2021-11-17' from dual union all
8 select 2, 3, date '2021-09-20' from dual union all
9 select 2, 3, date '2021-10-20' from dual
10 ),
11 temp as
12 -- rank rows per division/region, sorted by date column in descending order
13 (select t.*,
14 rank() over (partition by division, region order by datum desc) rnk
15 from test t
16 )
17 -- select up to 5 last rows per division/region
18 select division, region,
19 listagg(datum, ', ') within group (order by datum) dates,
20 trunc(sysdate) today,
21 --
22 (select trunc(sysdate) - a.datum
23 from temp a
24 where a.division = t.division
25 and a.region = t.region
26 and a.rnk = 1) days_since
27 from temp t
28 where rnk <= 5
29 group by division, region
30 order by division, region;
DIVISION REGION DATES TODAY DAYS_SINCE
---------- ---------- ------------------------------ ---------- ----------
1 2 11/18/2021, 11/20/2021 11/30/2021 10
1 7 10/18/2021, 11/19/2021 11/30/2021 11
2 2 11/17/2021 11/30/2021 13
2 3 09/20/2021, 10/20/2021 11/30/2021 41
SQL>

How to calculate the difference of HH:MM:SS between two dates in oracle sql?

I have a table abc as:
-- start_time |end_time | total_time_taken
-- 27.05.2020 00:52:48 |27.05.2020 02:08:33 |
I want to set the value of total_time_taken as the difference of end_time-start_time. in the format "HH:MM:SS".I searched the similar topic but didnot find the exact answer.
My expected output is like : 01:44:12 (HH:MM:SS)
So,i tried :
SELECT To_Char(end_time,'HH24:MM:SS'),To_Char(start_time,'HH24:MM:SS'),
To_Char(end_time,'HH24:MM:SS')-To_Char(start_time,'HH24:MM:SS') FROM abc;
The datatypes of start_time,end_time,total_time_taken is DATE.Please help me to find the solution.
If you cast those dates as timestamps, you can easily subtract them and see relatively nice result:
SQL> with test (st, et) as
2 (select to_date('27.05.2020 00:52:48', 'dd.mm.yyyy hh24:mi:ss'),
3 to_date('27.05.2020 02:08:33', 'dd.mm.yyyy hh24:mi:ss')
4 from dual
5 )
6 select cast(et as timestamp) - cast(st as timestamp) diff
7 from test;
DIFF
--------------------------------------------------------------------------
+000000000 01:15:45.000000
SQL>
If you want to format it as you wanted (note that mm format mask is for months; mi is for minutes), then you could do some extracting - again from timestamp (won't work for date):
SQL> with test (st, et) as
2 (select to_date('27.05.2020 00:52:48', 'dd.mm.yyyy hh24:mi:ss'),
3 to_date('27.05.2020 02:08:33', 'dd.mm.yyyy hh24:mi:ss')
4 from dual
5 ),
6 diff as
7 (select cast(et as timestamp) - cast(st as timestamp) diff
8 from test
9 )
10 select extract(hour from diff) ||':'||
11 extract(minute from diff) ||':'||
12 extract(second from diff) diff
13 from diff;
DIFF
-------------------------------------------------------------------------
1:15:45
SQL>
You can further make it pretty (e.g. two digits for hours, using LPAD function). Or, you can even write your own function which will actually work on difference of DATE datatype values, do some calculations (using trunc function, subtractions, whatnot), but the above looks pretty elegant if compared to a home-made function.
The answer by Littlefoot is perfectly fine. This answer is just to show there is more than one way to get the result.
First, we can subtract one date from another and get the difference in days, then convert that difference to an interval.
with test (st, et) as
(select to_date('27.05.2020 00:52:48', 'dd.mm.yyyy hh24:mi:ss'),
to_date('27.05.2020 02:08:33', 'dd.mm.yyyy hh24:mi:ss')
from dual
)
select numtodsinterval(et-st, 'day') diff
from test;
Then, since we can't control interval formatting directly, we can add DIFF to an arbitrary date and then use built-in date formatting.
with test (st, et) as
(select to_date('27.05.2020 00:52:48', 'dd.mm.yyyy hh24:mi:ss'),
to_date('27.05.2020 02:08:33', 'dd.mm.yyyy hh24:mi:ss')
from dual
)
select to_char(date '1-1-1' + numtodsinterval(et-st, 'day'), 'hh24:mi:ss') diff
from test;
DIFF
--------
01:15:45

Oracle APEX - converting a field from collection to type DATE

I have a page that grabs data from apex collection and one of the fields is date but since it is coming from collection it comes up as text. What is the best way to convert it to date?
Generally speaking, text (string) is converted to DATE with TO_DATE function, by applying the correct format mask. For example:
SQL> with test (text_value) as
2 (select '23.04.2019' from dual union all
3 select '04-2019-23' from dual union all
4 select '04 April 2019' from dual
5 )
6 select to_date(text_value, 'dd.mm.yyyy') result from test
7 where text_value = '23.04.2019'
8 union all
9 select to_date(text_value, 'mm-yyyy-dd') from test
10 where text_Value = '04-2019-23'
11 union all
12 select to_date(text_value, 'dd month yyyy', 'nls_date_language=english')
13 from test
14 where text_value = '04 April 2019'
15 /
RESULT
----------
23/04/2019
23/04/2019
04/04/2019
SQL>

Using a case when to know if date format is right

I want to migrate a table which contains some columns with dates. The issue is my dates are often in dd/mm/yyyyy HH24:MM:YYYY format. But sometimes it appears that the format is only dd/mm/yyyy, or blank.
I guess that's why I'm getting ORA-01830 when I'm trying to migrate the datas.
I tried
CASE
WHEN TO_DATE(MYDATE,'DD/MM/YYYY')
then TO_DATE(MYDATE,'DD/MM/YYYY 00:00:00')
END AS MYDATE
But I'm not sure if it is possible to test the date format (and ofcourse it's not working).
Thank you
TO_DATE cannot test date format, but you can do it. If Lalit's answer would not be enough, try something like
select
case when my_date like '__/__/__' then to_date(my_date, 'dd/mm/yy')
when my_date like '__-__-__' then to_date(my_date, 'dd-mm-yy')
...
end
So you have the data type issue. DATE is stored as string literal. As you have mentioned that the date model has the DD/MM/YYYY part same, just that the time portion is either missing for some rows or the entire value is NULL.
For example, let's say your table have the values like -
SQL> WITH dates AS(
2 SELECT 1 num, '29/12/2014 16:38:57' dt FROM dual UNION ALL
3 SELECT 2, '29/12/2014' FROM dual UNION ALL
4 SELECT 3, NULL FROM dual
5 )
6 SELECT num, dt
7 FROM dates
8 /
NUM DT
---------- -------------------
1 29/12/2014 16:38:57
2 29/12/2014
3
SQL>
TO_DATE with proper format model should do the trick.
Let's stick to a format model first.
SQL> alter session set nls_date_format='dd/mm/yyyy hh24:mi:ss';
Session altered.
Now, let's use TO_DATE to explicitly convert the string literal to date.
SQL> WITH dates AS(
2 SELECT 1 num, '29/12/2014 16:38:57' dt FROM dual UNION ALL
3 SELECT 2, '29/12/2014' FROM dual UNION ALL
4 SELECT 3, NULL FROM dual
5 )
6 SELECT num, to_date(dt, 'dd/mm/yyyy hh24:mi:ss') dt
7 FROM dates
8 /
NUM DT
---------- -------------------
1 29/12/2014 16:38:57
2 29/12/2014 00:00:00
3
SQL>

Get Gap between time range

In WORK_TIME column in my database table (EMP_WORKS), i have records as below.
WORK_TIME
19:03:00
20:00:00
21:02:00
21:54:00
23:04:00
00:02:00
i want to create a database view using these data. for it i need to get Gap between these times as below.
WORK_TIME GAP
19:03:00 -
20:00:00 00:57:00 (Gap between 19:03:00 and 20:00:00)
21:02:00 01:02:00 (Gap between 20:00:00 and 21:02:00)
21:54:00 00:52:00 (Gap between 21:02:00 and 21:54:00)
23:04:00 01:10:00 (Gap between 21:54:00 and 23:04:00)
00:02:00 00:58:00 (Gap between 23:04:00 and 00:02:00)
How could i do this ?
This query will get you the differences in hours:
SELECT
work_time,
( work_time - LAG(work_time) OVER (ORDER BY work_time) ) * 24 AS gap
FROM emp_works
Example on SQL Fiddle returns this:
WORK_TIME GAP
November, 07 2012 19:03:00+0000 (null)
November, 07 2012 20:00:00+0000 0.95
November, 07 2012 21:02:00+0000 1.033333333333
November, 07 2012 21:54:00+0000 0.866666666667
November, 07 2012 23:04:00+0000 1.166666666667
November, 08 2012 00:02:00+0000 0.966666666667
First you will need to have a primary key in the table containing the DATE/TIME field.
I have set up this demo on SQL Fiddle .. Have a look
I have represented the gap as a factor of hours between the two times. You can manipulate the figure to represent minutes, or days, whatever.
SELECT
TO_CHAR(A.WORK_TIME,'HH24:MI:SS') WORK_FROM,
TO_CHAR(B.WORK_TIME,'HH24:MI:SS') WORK_TO,
ROUND(24*(B.WORK_TIME-A.WORK_TIME),2) GAP FROM
sample A,
SAMPLE B
WHERE A.ID+1 = B.ID(+)
If your primary key values have difference greater than 1 (gaps within the values of the primary key) then you will need to offset the value dynamically like this:
SELECT
TO_CHAR(A.WORK_TIME,'HH24:MI:SS') WORK_FROM,
TO_CHAR(B.WORK_TIME,'HH24:MI:SS') WORK_TO,
ROUND(24*(B.WORK_TIME-A.WORK_TIME),2) GAP FROM
sample A,
SAMPLE B
WHERE b.ID = (select min(C.ID) from sample c where c.id>A.ID)
According to your desired result, provided in the question, you want to see time interval. And also I suppose that the WORK_TIME column is of date datatype and there is a date part(otherwise there will be a negative result of subtraction (previous value of WORK_TIME from 00.02.00)).
SQL> create table Work_times(
2 work_time
3 ) as
4 (
5 select to_date('01.01.2012 19:03:00', 'dd.mm.yyyy hh24:mi:ss') from dual union all
6 select to_date('01.01.2012 20:00:00', 'dd.mm.yyyy hh24:mi:ss') from dual union all
7 select to_date('01.01.2012 21:02:00', 'dd.mm.yyyy hh24:mi:ss') from dual union all
8 select to_date('01.01.2012 21:54:00', 'dd.mm.yyyy hh24:mi:ss') from dual union all
9 select to_date('01.01.2012 23:04:00', 'dd.mm.yyyy hh24:mi:ss') from dual union all
10 select to_date('02.01.2012 00:02:00', 'dd.mm.yyyy hh24:mi:ss') from dual
11 )
12 /
Table created
SQL>
SQL> select to_char(t.work_time, 'hh24.mi.ss') work_time
2 , (t.work_time -
3 lag(t.work_time) over(order by WORK_TIME)) day(1) to second(0) Res
4 from work_times t
5 ;
WORK_TIME RES
--------- -------------------------------------------------------------------------------
19.03.00
20.00.00 +0 00:57:00
21.02.00 +0 01:02:00
21.54.00 +0 00:52:00
23.04.00 +0 01:10:00
00.02.00 +0 00:58:00
6 rows selected

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