I want to group data based on date time in oracle
eg:-
03-DEC-13 06:12:03:23,
03-DEC-13 06:12:03:25,
04-DEC-13 08:12:03:23,
04-DEC-13 08:12:03:25
expected result :- 03-DEC-13 06:12:03, 04-DEC-13 08:12:03
neglect seconds.
SELECT DISTINCT trunc(some_date, 'MI') FROM some_table;
Question is not completely clear, but I think something like:
select to_char(datefield, 'DD-MMM-YY HH24:MI') , count(*) /* or other grouping */
from table
group by to_char(datefield, 'DD-MMM-YY HH24:MI')
If you want to include date/times for which you don't have a value, use something like join with a calendar table or a join with
select to_date('20000101', 'YYYYMMDD') + level / 24 day_and_hours
from dual
connect by level <= 100
Check your performance when doing so.
Related
Defining and selecting variable works just fine in Oracle SQL Developer.
ALTER SESSION SET NLS_LANGUAGE=english; -- First day of week
--DEFINE SUMMER_START_DT = TO_CHAR(TO_DATE('03-24-2022', 'MM-DD-YYYY'),'yyyymmdd')
DEFINE SUMMER_START_DT = TO_CHAR(NEXT_DAY(LAST_DAY(TO_DATE(TO_CHAR('01/03/' || (EXTRACT(YEAR FROM SYSDATE)-1 + level) || '02:00:00'),'DD/MM/YYYY HH24:MI:SS')) - INTERVAL '7' DAY, 'SUNDAY'),'yyyymmdd') FROM DUAL CONNECT BY level <=1
SELECT &SUMMER_START_DT;
But I get an error when trying to use the variable in Select statement using it as filter in the Where clause.
SELECT a.* FROM TRADE a WHERE TO_CHAR(a.TRADE_DATE_TIME,'yyyymmdd') = &SUMMER_START_DT;
I get the error "SQL command not properly ended"
Hope someone can help me. Thanks
Kind regards
Soren Sig Mikkelsen
You substitution variable includes from dual, which is OK when you just prepend select in your first example; but in the second you end up with two from clauses:
SELECT a.*
FROM TRADE a
WHERE TO_CHAR(a.TRADE_DATE_TIME,'yyyymmdd') =
TO_CHAR(NEXT_DAY(LAST_DAY(TO_DATE(TO_CHAR('01/03/' || (EXTRACT(YEAR FROM SYSDATE)-1 + level) || '02:00:00'),'DD/MM/YYYY HH24:MI:SS')) - INTERVAL '7' DAY, 'SUNDAY'),'yyyymmdd')
FROM DUAL CONNECT BY level <=1
(You can see that in the generated column name/alias in the output grid; or set verify on and run as a script.)
If you really wanted to use that as the right-hand side of the filter then you could enclose it in parentheses:
SELECT a.* FROM TRADE a WHERE TO_CHAR(a.TRADE_DATE_TIME,'yyyymmdd') = (SELECT &SUMMER_START_DT);
which would become:
SELECT a.*
FROM TRADE a
WHERE TO_CHAR(a.TRADE_DATE_TIME,'yyyymmdd') =
(
SELECT TO_CHAR(NEXT_DAY(LAST_DAY(TO_DATE(TO_CHAR('01/03/' || (EXTRACT(YEAR FROM SYSDATE)-1 + level) || '02:00:00'),'DD/MM/YYYY HH24:MI:SS')) - INTERVAL '7' DAY, 'SUNDAY'),'yyyymmdd')
FROM DUAL CONNECT BY level <=1
)
But the connect by isn't doing anything here, so you can remove that; and if you remove from dual as well then you can run your first statement as:
SELECT &SUMMER_START_DT FROM DUAL;
and the second as it is.
You could simplify the calculation though. For a start you aren't using the time element, so you don't need to make it 2am; and you can truncate to the start of the year and add two months to get March 1st; as a string if that's really what you want:
to_char(next_day(last_day(add_months(trunc(sysdate, 'YYYY'), 2)) - 7, 'SUNDAY'), 'YYYYMMDD')
db<>fiddle
But you can keep it as a date; if you:
DEFINE SUMMER_START_DT = next_day(last_day(add_months(trunc(sysdate, 'YYYY'), 2)) - 7, 'SUNDAY')
then again you can do:
SELECT &SUMMER_START_DT FROM DUAL;
and your second query can be:
SELECT a.*
FROM TRADE a
WHERE a.TRADE_DATE_TIME >= &SUMMER_START_DT
AND a.TRADE_DATE_TIME < &SUMMER_START_DT + 1
which avoids converting every TRADE_DATE_TIME date value to a string to compare it, and allows an index on that date column to be used.
I am trying to implement the same in redshift and i am finding it little difficult to do that. Since redshift is in top of postgresql engine, if any one can do it in postgresql it would be really helpfull. Basically the code gets the count for previous two month at column level. If there is no count for exact previous month then it gives 0.
This is my code:
with abc(dateval,cnt) as(
select 201908, 100 from dual union
select 201907, 200 from dual union
select 201906, 300 from dual union
select 201904, 600 from dual)
select dateval, cnt,
last_value(cnt) over (order by dateval
range between interval '1' month preceding
and interval '1' month preceding ) m1,
last_value(cnt) over (order by dateval
range between interval '2' month preceding
and interval '2' month preceding ) m2
from (select to_date(dateval, 'yyyymm') dateval, cnt from abc)
I get error in over by clause. I tried to give cast('1 month' as interval) but still its failing. Can someone please help me with this windows function.
expected output:
Regards
This is how I would do it. In Redshift there's no easy way to generate sequences, do I select row_number() from an arbitrary table to create a sequence:
with abc(dateval,cnt) as(
select 201908, 100 union
select 201907, 200 union
select 201906, 300 union
select 201904, 600),
cal(date) as (
select
add_months(
'20190101'::date,
row_number() over () - 1
) as date
from <an arbitrary table to generate a sequence of rows> limit 10
),
with_lag as (
select
dateval,
cnt,
lag(cnt, 1) over (order by date) as m1,
lag(cnt, 2) over (order by date) as m2
from abc right join cal on to_date(dateval, 'YYYYMM') = date
)
select * from with_lag
where dateval is not null
order by dateval
I am trying to create a month, year temp table that I can relate to in calculations, however I am having some issues. I am unable to create global temp tables due to restrictions and have to rely on the following kind of query.
WITH Months AS
(
SELECT LEVEL -1 AS ID
FROM DUAL
CONNECT BY LEVEL <=264
)
(SELECT
ROWNUM AS MO_SYS_ID,
TO_CHAR(ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), ID), 'YYYY'||'MM') AS MO_NM,
TO_CHAR(ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), ID), 'MON') AS MO_ABBR_NM,
TO_CHAR(ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), ID), 'MONTH') AS MO_FULL_NM,
TO_CHAR(ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), ID), 'MM')AS MO_NBR,
TO_CHAR(ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), ID), 'YYYY') AS YR_NBR
from Months;
What I really need to do is have this inserted into the temp table that I can recall. I do not have any fields that I can use from other tables either unfortunately. I need it to show 264 months from 1999.
Thank you
You can calculate a date column within the table expression, like this:
WITH Months AS (
SELECT LEVEL -1 AS ID, ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), LEVEL -1) as dt
FROM DUAL
CONNECT BY LEVEL <=264
)
SELECT *
from Months
If you are attempting to create date ranges, you could do this:
WITH Months AS (
SELECT LEVEL -1 AS ID
, ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), LEVEL -1) as start_dt
, ADD_MONTHS(TO_DATE('01/01/1999', 'DD/MM/YY'), LEVEL ) as end_dt
FROM DUAL
CONNECT BY LEVEL <=264
)
SELECT *
from yourtable t
inner join Months m on t.somecol >= m.start_dt and t.somecol < m.end_dt
Hello I need a formula in column ‘C’ which calculates/adds the amount of B Column based on the column A ID. If there are several amounts in same ID it should add the total amount and would show the result in column ‘C’ as a single row.
the output can be obtained from Oracle SQL query or an Excel formula.your help would be appreciated.
You can get the same output from Oracle itself, using analytical functions like below.
SUM() OVER(PARTITION BY ... ) -> This actually do the cumulative sum
WITH MYTABLE(ID,AMT) AS
(SELECT '2UF2', '500' FROM DUAL
UNION ALL
SELECT '2TC6', '300' FROM DUAL
UNION ALL
SELECT '2TC6', '200' FROM DUAL
UNION ALL
SELECT '2TC6', '800' FROM DUAL
)
SELECT ID,
AMT,
CASE ROW_NUMBER() OVER(PARTITION BY ID ORDER BY NULL)
WHEN 1
THEN SUM(AMT) OVER(PARTITION BY ID ORDER BY NULL)
END AS FORMULA
FROM MYTABLE
ORDER BY ID, FORMULA NULLS LAST;
SQL Fiddle Demo
You can use rollup in oracle
Select id,amt,sum (amt) nullFrom table nullGroup by rollup (id,amt)
For more details see below link
https://oracle-base.com/articles/misc/rollup-cube-grouping-functions-and-grouping-sets
In SQL you need an aggregation function, in this case sum, and a group by clause. The generic query should look like the following:
Select sum(b) from table group by a
I hope this helps.
The question I need to answer is this "What is the maximum number of page requests we have ever received in a 60 minute period?"
I have a table that looks similar to this:
date_page_requested date;
page varchar(80);
I'm looking for the MAX count of rows in any 60 minute timeslice.
I thought analytic functions might get me there but so far I'm drawing a blank.
I would love a pointer in the right direction.
You have some options in the answer that will work, here is one that uses Oracle's "Windowing Functions with Logical Offset" feature instead of joins or correlated subqueries.
First the test table:
Wrote file afiedt.buf
1 create table t pctfree 0 nologging as
2 select date '2011-09-15' + level / (24 * 4) as date_page_requested
3 from dual
4* connect by level <= (24 * 4)
SQL> /
Table created.
SQL> insert into t values (to_date('2011-09-15 11:11:11', 'YYYY-MM-DD HH24:Mi:SS'));
1 row created.
SQL> commit;
Commit complete.
T now contains a row every quarter hour for a day with one additional row at 11:11:11 AM. The query preceeds in three steps. Step 1 is to, for every row, get the number of rows that come within the next hour after the time of the row:
1 with x as (select date_page_requested
2 , count(*) over (order by date_page_requested
3 range between current row
4 and interval '1' hour following) as hour_count
5 from t)
Then assign the ordering by hour_count:
6 , y as (select date_page_requested
7 , hour_count
8 , row_number() over (order by hour_count desc, date_page_requested asc) as rn
9 from x)
And finally select the earliest row that has the greatest number of following rows.
10 select to_char(date_page_requested, 'YYYY-MM-DD HH24:Mi:SS')
11 , hour_count
12 from y
13* where rn = 1
If multiple 60 minute windows tie in hour count, the above will only give you the first window.
This should give you what you need, the first row returned should have
the hour with the highest number of pages.
select number_of_pages
,hour_requested
from (select to_char(date_page_requested,'dd/mm/yyyy hh') hour_requested
,count(*) number_of_pages
from pages
group by to_char(date_page_requested,'dd/mm/yyyy hh')) p
order by number_of_pages
How about something like this?
SELECT TOP 1
ranges.date_start,
COUNT(data.page) AS Tally
FROM (SELECT DISTINCT
date_page_requested AS date_start,
DATEADD(HOUR,1,date_page_requested) AS date_end
FROM #Table) ranges
JOIN #Table data
ON data.date_page_requested >= ranges.date_start
AND data.date_page_requested < ranges.date_end
GROUP BY ranges.date_start
ORDER BY Tally DESC
For PostgreSQL, I'd first probably write something like this for a "window" aligned on the minute. You don't need OLAP windowing functions for this.
select w.ts,
date_trunc('minute', w.ts) as hour_start,
date_trunc('minute', w.ts) + interval '1' hour as hour_end,
(select count(*)
from weblog
where ts between date_trunc('minute', w.ts) and
(date_trunc('minute', w.ts) + interval '1' hour) ) as num_pages
from weblog w
group by ts, hour_start, hour_end
order by num_pages desc
Oracle also has a trunc() function, but I'm not sure of the format. I'll either look it up in a minute, or leave to see a friend's burlesque show.
WITH ranges AS
( SELECT
date_page_requested AS StartDate,
date_page_requested + (1/24) AS EndDate,
ROWNUMBER() OVER(ORDER BY date_page_requested) AS RowNo
FROM
#Table
)
SELECT
a.StartDate AS StartDate,
MAX(b.RowNo) - a.RowNo + 1 AS Tally
FROM
ranges a
JOIN
ranges b
ON a.StartDate <= b.StartDate
AND b.StartDate < a.EndDate
GROUP BY a.StartDate
, a.RowNo
ORDER BY Tally DESC
or:
WITH ranges AS
( SELECT
date_page_requested AS StartDate,
date_page_requested + (1/24) AS EndDate,
ROWNUMBER() OVER(ORDER BY date_page_requested) AS RowNo
FROM
#Table
)
SELECT
a.StartDate AS StartDate,
( SELECT MIN(b.RowNo) - a.RowNo
FROM ranges b
WHERE b.StartDate > a.EndDate
) AS Tally
FROM
ranges a
ORDER BY Tally DESC