I need a query which will output a list of dates between two given dates.
For example, if my start date is 23/02/2016 and end date is 02/03/2016, I am expecting the following output:
Date
----
23/02/2016
24/02/2016
25/02/2016
26/02/2016
27/02/2016
28/02/2016
29/02/2016
01/03/2016
02/03/2016
Also, I need the above using SQL only (without the use of 'WITH' statement or tables). Please help.
I am using ,ostly DB2 for iSeries, so I will give you an SQL only solution that works on it. Currently I don't have an access to the server, so the query is not tested but it should work. EDIT Query is already tested and working
SELECT
d.min + num.n DAYS
FROM
-- create inline table with min max date
(VALUES(DATE('2015-02-28'), DATE('2016-03-01'))) AS d(min, max)
INNER JOIN
-- create inline table with numbers from 0 to 999
(
SELECT
n1.n + n10.n + n100.n AS n
FROM
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) AS n1(n)
CROSS JOIN
(VALUES(0),(10),(20),(30),(40),(50),(60),(70),(80),(90)) AS n10(n)
CROSS JOIN
(VALUES(0),(100),(200),(300),(400),(500),(600),(700),(800),(900)) AS n100(n)
) AS num
ON
d.min + num.n DAYS<= d.max
ORDER BY
num.n;
if you don't want to execute the query only once, you should consider creating a real table with values for the loop:
CREATE TABLE dummy_loop AS (
SELECT
n1.n + n10.n + n100.n AS n
FROM
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) AS n1(n)
CROSS JOIN
(VALUES(0),(10),(20),(30),(40),(50),(60),(70),(80),(90)) AS n10(n)
CROSS JOIN
(VALUES(0),(100),(200),(300),(400),(500),(600),(700),(800),(900)) AS n100(n)
) WITH DATA;
ALTER TABLE dummy_loop ADD PRIMARY KEY (dummy_loop.n);
It depends on the reason for which you like to use it, but you could even create table for lets say for 100 years. It will be only 100*365 = 36500 rows with just a date field, so the table will be quite small and fast for joins.
CREATE TABLE dummy_dates AS (
SELECT
DATE('1970-01-01') + (n1.n + n10.n + n100.n) DAYS AS date
FROM
(VALUES(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) AS n1(n)
CROSS JOIN
(VALUES(0),(10),(20),(30),(40),(50),(60),(70),(80),(90)) AS n10(n)
CROSS JOIN
(VALUES(0),(100),(200),(300),(400),(500),(600),(700),(800),(900)) AS n100(n)
) WITH DATA;
ALTER TABLE dummy_dates ADD PRIMARY KEY (dummy_dates.date);
And the select query could look like:
SELECT
*
FROM
dummy_days
WHERE
date BETWEEN(:startDate, :endDate);
EDIT 2: Thanks to #Lennart suggestion I have changed TABLE(VALUES(..,..,..)) to VALES(..,..,..) because as he said TABLE is a synonym to LATERAL that was a real surprise for me.
EDIT 3: Thanks to #godric7gt I have removed TIMESTAMPDIFF and will remove from all my scripts, because as it is said in the documentation:
These assumptions are used when converting the information in the second argument, which is a timestamp duration, to the interval type specified in the first argument. The returned estimate may vary by a number of days. For example, if the number of days (interval 16) is requested for the difference between '1997-03-01-00.00.00' and '1997-02-01-00.00.00', the result is 30. This is because the difference between the timestamps is 1 month, and the assumption of 30 days in a month applies.
It was a real surprise, because I was always trust this function for days difference.
For generating rows recusive SQL will needed.
Usually this looks like this in DB2:
with temp (date) as (
select date('23.02.2016') as date from sysibm.sysdummy1
union all
select date + 1 day from temp
where date < date('02.03.2016')
)
select * from temp
For whatever reason a CTE (using WITH) should be avoided.
A possible workaround would be setting
db2set DB2_COMPATIBILITY_VECTOR=8
which enables the use of the Oracle style recusion with CONNECT BY
SELECT date('22.02.2016') + level days as dt
FROM sysibm.sysdummy1 CONNECT BY date('22.02.2016') + level days <= date('02.03.2016')
Please note: after setting the DB2_COMPATIBILITY_VECTOR a instance restart is necessary.
This solution doesn't use WITH, but it does use WHILE and a temp table...hopefully that meets your needs still?
EDIT -- I built this in SSMS 2014
DECLARE #Start DATE
DECLARE #End DATE
SET #Start = '2016-02-23'
SET #End = '2016-03-02'
CREATE TABLE #Dates ([Date] DATE)
WHILE #Start <= #End
BEGIN
INSERT INTO #Dates
SELECT #Start
SET #Start = DATEADD(Day,1,#Start)
END
SELECT * FROM #Dates
DROP TABLE #Dates
I assume AS400 does not support recursive CTE's, and that's why you want a solution without them. I have no clue whether it supports any of the following constructions, but it might be worth a shot. First we will need a generator, any table with a sufficient number of rows will do. If you don't have a table large enough for the number of days you want you can create a cartesian product. Example:
select row_number() over ()
from a_table
cross join a_table
Another way of extending the domain is to create the powerset of a table using group by cube, see below.
Assume we one way or another can create a large enough set of rows. You can generate the dates like:
select date('23/02/2016') + n days
from (
select row_number() over () as n
from a_table
) as t
where n < 100
order by n
If for some reason you don't want to use an existing table, group by cube will produce a relation with a cardinality equal to the power set of the attributes. Here I use 4 columns which will generate 16 rows.
select date('2016-01-01') + row_number() over () days
from sysibm.dual x
group by cube(x.dummy, x.dummy, x.dummy, x.dummy)
If you want to generate say 100 rows you need 7 (since 2^7=128) attributes in the group by cube clause and a fetch first 100 rows:
select date('2016-01-01') + row_number() over () days
from sysibm.dual x
group by cube(x.dummy, x.dummy, x.dummy, x.dummy, x.dummy, x.dummy, x.dummy)
order by 1
fetch first 100 rows only
I want to select rows for a field MRD which is declared as date where it is prior for that date only.
So
(case when sum (transPoints) > 4 and MRD is that same date then 4
So if a row has a date of today, I want the case when to be triggered when the transaction points are bigger than 4 against all columns with the same date.
As you can imagine the date field will be different against many rows.
Based on what I can understand from your question, it seems that the GROUP BY clause may be what you're looking for. If your date column is in the correct format then you may have to use something like:
SELECT CAST(DateColumn as DATE)
FROM YourTable
GROUP BY CAST(DateColumn as DATE)
I have a table dbo.X with DateTime column Y which may have hundreds of records.
My Stored Procedure has parameter #CurrentDate, I want to find out the date in the column Y in above table dbo.X which is less than and closest to #CurrentDate.
How to find it?
The where clause will match all rows with date less than #CurrentDate and, since they are ordered descendantly, the TOP 1 will be the closest date to the current date.
SELECT TOP 1 *
FROM x
WHERE x.date < #CurrentDate
ORDER BY x.date DESC
Use DateDiff and order your result by how many days or seconds are between that date and what the Input was
Something like this
select top 1 rowId, dateCol, datediff(second, #CurrentDate, dateCol) as SecondsBetweenDates
from myTable
where dateCol < #currentDate
order by datediff(second, #CurrentDate, dateCol)
I have a better solution for this problem i think.
I will show a few images to support and explain the final solution.
Background
In my solution I have a table of FX Rates. These represent market rates for different currencies. However, our service provider has had a problem with the rate feed and as such some rates have zero values. I want to fill the missing data with rates for that same currency that as closest in time to the missing rate. Basically I want to get the RateId for the nearest non zero rate which I will then substitute. (This is not shown here in my example.)
1) So to start off lets identify the missing rates information:
Query showing my missing rates i.e. have a rate value of zero
2) Next lets identify rates that are not missing.
Query showing rates that are not missing
3) This query is where the magic happens. I have made an assumption here which can be removed but was added to improve the efficiency/performance of the query. The assumption on line 26 is that I expect to find a substitute transaction on the same day as that of the missing / zero transaction.
The magic happens is line 23: The Row_Number function adds an auto number starting at 1 for the shortest time difference between the missing and non missing transaction. The next closest transaction has a rownum of 2 etc.
Please note that in line 25 I must join the currencies so that I do not mismatch the currency types. That is I don't want to substitute a AUD currency with CHF values. I want the closest matching currencies.
Combining the two data sets with a row_number to identify nearest transaction
4) Finally, lets get data where the RowNum is 1
The final query
The query full query is as follows;
; with cte_zero_rates as
(
Select *
from fxrates
where (spot_exp = 0 or spot_exp = 0)
),
cte_non_zero_rates as
(
Select *
from fxrates
where (spot_exp > 0 and spot_exp > 0)
)
,cte_Nearest_Transaction as
(
select z.FXRatesID as Zero_FXRatesID
,z.importDate as Zero_importDate
,z.currency as Zero_Currency
,nz.currency as NonZero_Currency
,nz.FXRatesID as NonZero_FXRatesID
,nz.spot_imp
,nz.importDate as NonZero_importDate
,DATEDIFF(ss, z.importDate, nz.importDate) as TimeDifferece
,ROW_NUMBER() Over(partition by z.FXRatesID order by abs(DATEDIFF(ss, z.importDate, nz.importDate)) asc) as RowNum
from cte_zero_rates z
left join cte_non_zero_rates nz on nz.currency = z.currency
and cast(nz.importDate as date) = cast(z.importDate as date)
--order by z.currency desc, z.importDate desc
)
select n.Zero_FXRatesID
,n.Zero_Currency
,n.Zero_importDate
,n.NonZero_importDate
,DATEDIFF(s, n.NonZero_importDate,n.Zero_importDate) as Delay_In_Seconds
,n.NonZero_Currency
,n.NonZero_FXRatesID
from cte_Nearest_Transaction n
where n.RowNum = 1
and n.NonZero_FXRatesID is not null
order by n.Zero_Currency, n.NonZero_importDate
It's quite a hard one to explain but probably (hopefully) an easy one to solve so I'll just explain what it is I'm trying to achieve.
I have a table where multiple logs can be entered for a day each as a seperate row, I then have a decimal as another column, I'm trying to create a summary for each day which would be something like
01/01/1900 | | 5.5
When there's one entry for the 01/01/1900 with 2.5, one with 3 in the main table so adding the values together for the day?
My only issue is adding the dates together if the dates the same, I was thinking something like
Select distinct date and joining it with a table that gets the sum of the decimal column where date is... and that's where im not too sure?
Any help would be great! thanks
If your table is named logs with data like
log_date | value
1900-01-01 | 2.5
1900-01-01 | 3
then your query is
SELECT sum(value) FROM logs GROUP BY log_date
What you're looking for is probably a GROUP BY clause.
SELECT [ yourdatecol, ] sum(yourdecimalcol) FROM yourtable
[ WHERE yourdatecol = .. ]
GROUP BY [ get_ymd_from_date(yourdatecol) | yourdatecol ] ;
With such syntax you'll get sum of row sets, selected by the same datecol value. You may also want to approximate date ( e.g. taking only Y/M/D part from it ), if date contains H/M/ss and what you want is per-day sums. Optional parts I enclosed in square brackets.
SELECT log_date,sum(value) FROM logs GROUP BY log_date
CREATE VIEW Summary
AS
SELECT
DateValue,
SUM(DecimalValue) DayTotal
FROM
EventTable
GROUP BY
DateValue;
Then
SELECT
*
FROM
Summary
WHERE
DateValue = '1900-01-01'
Try this :
SELECT CONVERT(VARCHAR, DateColumn, 103) AS OutputDate, SUM(ValueColumn) AS TotalValue
FROM YourTable
GROUP BY CONVERT(VARCHAR, DateColumn, 103)
I'm presuming a DateTime is used, lets call it logdate. I'm also presuming the other one is a decimal, lets call it logdecimal.
Using SQL server 2008 you can do (the is a type called date which is without the time-part):
SELECT
CAST(logdate as date) as TheDay,
SUM(logdecimal) as TheSum
FROM logTable
GROUP BY CAST(logdatetime as date)
Using a SQL server without the type date, maybe something like:
SELECT
CONVERT(varchar(10), logdate, 101) as TheDay,
SUM(logdecimal) as TheSum
FROM logTable
GROUP BY CONVERT(varchar(10), logdate , 101)
Regards, Olle
Edit: This one will work if it is a DateTime (including time part) you want to group as a date (not including time part). Looks like this was not the case in this question.
I have a table with sequential timestamps:
2011-03-17 10:31:19
2011-03-17 10:45:49
2011-03-17 10:47:49
...
I need to find the average time difference between each of these(there could be dozens) in seconds or whatever is easiest, I can work with it from there. So for example the above inter-arrival time for only the first two times would be 870 (14m 30s). For all three times it would be: (870 + 120)/2 = 445 (7m 25s).
A note, I am using postgreSQL 8.1.22 .
EDIT: The table I mention above is from a different query that is literally just a one-column list of timestamps
Not sure I understood your question completely, but this might be what you are looking for:
SELECT avg(difference)
FROM (
SELECT timestamp_col - lag(timestamp_col) over (order by timestamp_col) as difference
FROM your_table
) t
The inner query calculates the distance between each row and the preceding row. The result is an interval for each row in the table.
The outer query simply does an average over all differences.
i think u want to find avg(timestamptz).
my solution is avg(current - min value). but since result is interval, so add it to min value again.
SELECT avg(target_col - (select min(target_col) from your_table))
+ (select min(target_col) from your_table)
FROM your_table
If you cannot upgrade to a version of PG that supports window functions, you
may compute your table's sequential steps "the slow way."
Assuming your table is "tbl" and your timestamp column is "ts":
SELECT AVG(t1 - t0)
FROM (
-- All this silliness would be moot if we could use
-- `` lead(ts) over (order by ts) ''
SELECT tbl.ts AS t0,
next.ts AS t1
FROM tbl
CROSS JOIN
tbl next
WHERE next.ts = (
SELECT MIN(ts)
FROM tbl subquery
WHERE subquery.ts > tbl.ts
)
) derived;
But don't do that. Its performance will be terrible. Please do what
a_horse_with_no_name suggests, and use window functions.