I have a data set as shown in the picture.
I am trying to get the date difference between eligenddate (First row) and eligstartdate (second row). I would really appreciate any suggestions.
Thank you
SQL2005:
One solution is to insert into a table variable (#DateWithRowNum - the number of rows is small) or into a temp table (#DateWithRowNum - the number of rows is high) the rows with a row number (generated using [elig]startdate as order by criteria; also see note #1) plus a self join thus:
DECLARE #DateWithRowNum TABLE (
memberid VARCHAR(50) NOT NULL,
rownum INT,
PRIMARY KEY(memberid, rownum),
startdate DATETIME NOT NULL,
enddate DATETIME NOT NULL
)
INSERT #DateWithRowNum (memberid, rownum, startdate, enddate)
SELECT memberid,
ROW_NUMBER() OVER(PARTITION BY memberid ORDER By startdate),
startdate,
enddate
FROM dbo.MyTable
SELECT crt.*, DATEDIFF(MONTH, crt.enddate, prev.startdate) AS gap
FROM #DateWithRowNum crt
LEFT JOIN #DateWithRowNum prev ON crt.memberid = prev.memberid AND crt.rownum - 1 = prev.rownum
ORDER BY crt.memberid, crt.rownum
Another solution is to use common table expression instead of table variable / temp table thus:
;WITH DateWithRowNum AS (
SELECT memberid,
ROW_NUMBER() OVER(PARTITION BY memberid ORDER By startdate),
startdate,
enddate
FROM dbo.MyTable
)
SELECT crt.*, DATEDIFF(MONTH, crt.enddate, prev.startdate) AS gap
FROM DateWithRowNum crt
LEFT /*HASH*/ JOIN DateWithRowNum prev ON crt.memberid = prev.memberid AND crt.rownum - 1 = prev.rownum
ORDER BY crt.memberid, crt.rownum
Note #1: I assume that you need to calculate these values for every memberid
Note #2: HASH hint forces SQL Server to evaluate just once every data source (crt or prev) of LEFT JOIN.
Related
I have a table of item price changes, and I want to use it to create a table of item prices for each date (between the item's launch and end dates).
Here's some code to create the date:-
declare #Item table (item_id int, item_launch_date date, item_end_date date);
insert into #Item Values (1,'2001-01-01','2016-01-01'), (2,'2001-01-01','2016-01-01')
declare #ItemPriceChanges table (item_id int, item_price money, my_date date);
INSERT INTO #ItemPriceChanges VALUES (1, 123.45, '2001-01-01'), (1, 345.34, '2001-01-03'), (2, 34.34, '2001-01-01'), (2,23.56 , '2005-01-01'), (2, 56.45, '2016-05-01'), (2, 45.45, '2017-05-01'); ;
What I'd like to see is something like this:-
item_id date price
------- ---- -----
1 2001-01-01 123.45
1 2001-01-02 123.45
1 2001-01-03 345.34
1 2001-01-04 345.34
etc.
2 2001-01-01 34.34
2 2001-01-02 34.34
etc.
Any suggestions on how to write the query?
I'm using SQL Server 2016.
Added:
I also have a calendar table called "dim_calendar" with one row per day. I had hoped to use a windowing function, but the nearest I can find is lead() and it doesn't do what I thought it would do:-
select
i.item_id,
c.day_date,
ipc.item_price as item_price_change,
lead(item_price,1,NULL) over (partition by i.item_id ORDER BY c.day_date) as item_price
from dim_calendar c
inner join #Item i
on c.day_date between i.item_launch_date and i.item_end_date
left join #ItemPriceChanges ipc
on i.item_id=ipc.item_id
and ipc.my_date=c.day_date
order by
i.item_id,
c.day_date;
Thanks
I wrote this prior to your edit. Note that your sample output suggests that an item can have two prices on the day of the price change. The following assumes that an item can only have one price on a price change day and that is the new price.
declare #Item table (item_id int, item_launch_date date, item_end_date date);
insert into #Item Values (1,'2001-01-01','2016-01-01'), (2,'2001-01-01','2016-01-01')
declare #ItemPriceChange table (item_id int, item_price money, my_date date);
INSERT INTO #ItemPriceChange VALUES (1, 123.45, '2001-01-01'), (1, 345.34, '2001-01-03'), (2, 34.34, '2001-01-01'), (2,23.56 , '2005-01-01'), (2, 56.45, '2016-05-01'), (2, 45.45, '2017-05-01');
SELECT * FROM #ItemPriceChange
-- We need a table variable holding all possible date points for the output
DECLARE #DatePointList table (DatePoint date);
DECLARE #StartDatePoint date = '01-Jan-2001';
DECLARE #MaxDatePoint date = GETDATE();
DECLARE #DatePoint date = #StartDatePoint;
WHILE #DatePoint <= #MaxDatePoint BEGIN
INSERT INTO #DatePointList (DatePoint)
SELECT #DatePoint;
SET #DatePoint = DATEADD(DAY,1,#DatePoint);
END;
-- We can use a CTE to sequence the price changes
WITH ItemPriceChange AS (
SELECT item_id, item_price, my_date, ROW_NUMBER () OVER (PARTITION BY Item_id ORDER BY my_date ASC) AS SeqNo
FROM #ItemPriceChange
)
-- With the price changes sequenced, we can derive from and to dates for each price and use a join to the table of date points to produce the output. Also, use an inner join back to #item to only return rows for dates that are within the start/end date of the item
SELECT ItemPriceDate.item_id, DatePointList.DatePoint, ItemPriceDate.item_price
FROM #DatePointList AS DatePointList
INNER JOIN (
SELECT ItemPriceChange.item_id, ItemPriceChange.item_price, ItemPriceChange.my_date AS from_date, ISNULL(ItemPriceChange_Next.my_date,#MaxDatePoint) AS to_date
FROM ItemPriceChange
LEFT OUTER JOIN ItemPriceChange AS ItemPriceChange_Next ON ItemPriceChange_Next.item_id = ItemPriceChange.item_id AND ItemPriceChange.SeqNo = ItemPriceChange_Next.SeqNo - 1
) AS ItemPriceDate ON DatePointList.DatePoint >= ItemPriceDate.from_date AND DatePointList.DatePoint < ItemPriceDate.to_date
INNER JOIN #item AS item ON item.item_id = ItemPriceDate.item_id AND DatePointList.DatePoint BETWEEN item.item_launch_date AND item.item_end_date
ORDER BY ItemPriceDate.item_id, DatePointList.DatePoint;
#AlphaStarOne Perfect! I've modified it to use a Windowing function rather than a self-join, but what you've suggested works. Here's my implementation of that in case anyone else needs it:
SELECT
ipd.item_id,
dc.day_date,
ipd.item_price
FROM dim_calendar dc
INNER JOIN (
SELECT
item_id,
item_price,
my_date AS from_date,
isnull(lead(my_date,1,NULL) over (partition by item_id ORDER BY my_date),getdate()) as to_date
FROM #ItemPriceChange ipc1
) AS ipd
ON dc.day_date >= ipd.from_date
AND dc.day_date < ipd.to_date
INNER JOIN #item AS i
ON i.item_id = ipd.item_id
AND dc.day_date BETWEEN i.item_launch_date AND i.item_end_date
ORDER BY
ipd.item_id,
dc.day_date;
I have two tables which I need to combine as sometimes some dates are found in table A and not in table B and vice versa. My desired result is that for those overlaps on consecutive days be combined.
I'm using PostgreSQL.
Table A
id startdate enddate
--------------------------
101 12/28/2013 12/31/2013
Table B
id startdate enddate
--------------------------
101 12/15/2013 12/15/2013
101 12/16/2013 12/16/2013
101 12/28/2013 12/28/2013
101 12/29/2013 12/31/2013
Desired Result
id startdate enddate
-------------------------
101 12/15/2013 12/16/2013
101 12/28/2013 12/31/2013
Right. I have a query that I think works. It certainly works on the sample records you provided. It uses a recursive CTE.
First, you need to merge the two tables. Next, use a recursive CTE to get the sequences of overlapping dates. Finally, get the start and end dates, and join back to the "merged" table to get the id.
with recursive allrecords as -- this merges the input tables. Add a unique row identifier
(
select *, row_number() over (ORDER BY startdate) as rowid from
(select * from table1
UNION
select * from table2) a
),
path as ( -- the recursive CTE. This gets the sequences
select rowid as parent,rowid,startdate,enddate from allrecords a
union
select p.parent,b.rowid,b.startdate,b.enddate from allrecords b join path p on (p.enddate + interval '1 day')>=b.startdate and p.startdate <= b.startdate
)
SELECT id,g.startdate,g.enddate FROM -- outer query to get the id
-- inner query to get the start and end of each sequence
(select parent,min(startdate) as startdate, max(enddate) as enddate from
(
select *, row_number() OVER (partition by rowid order by parent,startdate) as row_number from path
) a
where row_number = 1 -- We only want the first occurrence of each record
group by parent)g
INNER JOIN allrecords a on a.rowid = parent
The below fragment does what you intend. (but it will probably be very slow) The problem is that detecteng (non)overlapping dateranges is impossible with standard range operators, since a range could be split into two parts.
So, my code does the following:
split the dateranges from table_A into atomic records, with one date per record
[the same for table_b]
cross join these two tables (we are only interested in A_not_in_B, and B_not_in_A) , remembering which of the L/R outer join wings it came from.
re-aggregate the resulting records into date ranges.
-- EXPLAIN ANALYZE
--
WITH RECURSIVE ranges AS (
-- Chop up the a-table into atomic date units
WITH ar AS (
SELECT generate_series(a.startdate,a.enddate , '1day'::interval)::date AS thedate
, 'A'::text AS which
, a.id
FROM a
)
-- Same for the b-table
, br AS (
SELECT generate_series(b.startdate,b.enddate, '1day'::interval)::date AS thedate
, 'B'::text AS which
, b.id
FROM b
)
-- combine the two sets, retaining a_not_in_b plus b_not_in_a
, moments AS (
SELECT COALESCE(ar.id,br.id) AS id
, COALESCE(ar.which, br.which) AS which
, COALESCE(ar.thedate, br.thedate) AS thedate
FROM ar
FULL JOIN br ON br.id = ar.id AND br.thedate = ar.thedate
WHERE ar.id IS NULL OR br.id IS NULL
)
-- use a recursive CTE to re-aggregate the atomic moments into ranges
SELECT m0.id, m0.which
, m0.thedate AS startdate
, m0.thedate AS enddate
FROM moments m0
WHERE NOT EXISTS ( SELECT * FROM moments nx WHERE nx.id = m0.id AND nx.which = m0.which
AND nx.thedate = m0.thedate -1
)
UNION ALL
SELECT rr.id, rr.which
, rr.startdate AS startdate
, m1.thedate AS enddate
FROM ranges rr
JOIN moments m1 ON m1.id = rr.id AND m1.which = rr.which AND m1.thedate = rr.enddate +1
)
SELECT * FROM ranges ra
WHERE NOT EXISTS (SELECT * FROM ranges nx
-- suppress partial subassemblies
WHERE nx.id = ra.id AND nx.which = ra.which
AND nx.startdate = ra.startdate
AND nx.enddate > ra.enddate
)
;
Im a new in TSQL.
I have a table with a field called ODOMETER of a vehicle. I have to get the quantity of km in a period of time from 1st of the month to the end.
SELECT MAX(Odometer) - MIN(Odometer) as TotalKm FROM Table
This will work in ideal test scenary, but the Odomometer can be reset to 0 in anytime.
Someone can help to solve my problem, thank you.
I'm working with MS SQL 2012
EXAMPLE of records:
Date Odometer value
datetime var, 37210
datetime var, 37340
datetime var, 0
datetime var, 220
Try something like this using the LAG. There are other ways, but this should be easy.
EDIT: Changing the sample data to include records outside of the desired month range. Also simplifying that Reading for easy hand calc. Will shows a second option as siggested by OP.
DECLARE #tbl TABLE (stamp DATETIME, Reading INT)
INSERT INTO #tbl VALUES
('02/28/2014',0)
,('03/01/2014',10)
,('03/10/2014',20)
,('03/22/2014',0)
,('03/30/2014',10)
,('03/31/2014',20)
,('04/01/2014',30)
--Original solution with WHERE on the "outer" SELECT.
--This give a result of 40 as it include the change of 10 between 2/28 and 3/31.
;WITH cte AS (
SELECT Reading
,LAG(Reading,1,Reading) OVER (ORDER BY stamp ASC) LastReading
,Reading - LAG(Reading,1,Reading) OVER (ORDER BY stamp ASC) ChangeSinceLastReading
,CONVERT(date, stamp) stamp
FROM #tbl
)
SELECT SUM(CASE WHEN Reading = 0 THEN 0 ELSE ChangeSinceLastReading END)
FROM cte
WHERE stamp BETWEEN '03/01/2014' AND '03/31/2014'
--Second option with WHERE on the "inner" SELECT (within the CTE)
--This give a result of 30 as it include the change of 10 between 2/28 and 3/31 is by the filtered lag.
;WITH cte AS (
SELECT Reading
,LAG(Reading,1,Reading) OVER (ORDER BY stamp ASC) LastReading
,Reading - LAG(Reading,1,Reading) OVER (ORDER BY stamp ASC) ChangeSinceLastReading
,CONVERT(date, stamp) stamp
FROM #tbl
WHERE stamp BETWEEN '03/01/2014' AND '03/31/2014'
)
SELECT SUM(CASE WHEN Reading = 0 THEN 0 ELSE ChangeSinceLastReading END)
FROM cte
I think Karl solution using LAG is better than mine, but anyway:
;WITH [Rows] AS
(
SELECT o1.[Date], o1.[Value] as CurrentValue,
(SELECT TOP 1 o2.[Value]
FROM #tbl o2 WHERE o1.[Date] < o2.[Date]) as NextValue
FROM #tbl o1
)
SELECT SUM (CASE WHEN [NextValue] IS NULL OR [NextValue] < [CurrentValue] THEN 0 ELSE [NextValue] - [CurrentValue] END )
FROM [Rows]
Hy
my problem is, that I need the average time between a chargebegin & chargeend row (timestampserver) grouped by stationname and connectornumber and day.
The main problem is, that i can not use a Max oder Min function because I have the same stationname/connecternumber combination several times in the table.
So in fact I have to select the first chargebegin and find the next chargeend (the one with the same station/connectornumber combination and the min(id) > chargebegin.id) to get the difference.
I tried a lot but in fact i have no idea how to do this.
Database is postgresql 9.2
Testdata:
create table datatable (
id int,
connectornumber int,
message varchar,
metercount int,
stationname varchar,
stationuser varchar,
timestampmessage varchar,
timestampserver timestamp,
authsource varchar
);
insert into datatable values (181,1,'chargebegin',4000,'100','FCSC','2012-10-10 16:39:10','2012-10-10 16:39:15.26');
insert into datatable values (182,1,'chargeend',4000,'100','FCSC','2012-10-10 16:39:17','2012-10-10 16:39:28.379');
insert into datatable values (184,1,'chargebegin',4000,'100','FCSC','2012-10-11 11:06:31','2012-10-11 11:06:44.981');
insert into datatable values (185,1,'chargeend',4000,'100','FCSC','2012-10-11 11:16:09','2012-10-11 11:16:10.669');
insert into datatable values (191,1,'chargebegin',4000,'100','MSISDN_100','2012-10-11 13:38:19','2012-10-11 13:38:26.583');
insert into datatable values (192,1,'chargeend',4000,'100','MSISDN_100','2012-10-11 13:38:53','2012-10-11 13:38:55.631');
insert into datatable values (219,1,'chargebegin',4000,'100','MSISDN_','2012-10-12 11:38:03','2012-10-12 11:38:29.029');
insert into datatable values (220,1,'chargeend',4000,'100','MSISDN_','2012-10-12 11:40:14','2012-10-12 11:40:18.635');
This might have some syntax errors as I can't test it right now, but you should get an idea, how to solve it.
with
chargebegin as (
select
stationname,
connectornumber,
timestampserver,
row_number() over(partition by stationname, connectornumber order by timestampserver) as rn
from
datatable
where
message = 'chargebegin'
),
chargeend as (
select
stationname,
connectornumber,
timestampserver,
row_number() over(partition by stationname, connectornumber order by timestampserver) as rn
from
datatable
where
message = 'chargeend'
)
select
stationname,
connectornumber,
avg(b.timestampserver - a.timestampserver) as avg_diff
from
chargebegin a
join chargeend b using (stationname, connectornumber, rn)
group by
stationname,
connectornumber
This assumes that there is always end event for begin event and that these event cannot overlap (means that for stationname and connectornumber, there can be only one connection at any time). Therefore you can user row_number() to get matching begin/end events and then do whatever calculation is needed.
I have 2 tables, one containing meter IDs, and another containing measurements for some of the meters in the first table. This is the table structure:
MeterConfig:
MeterID (int)
MeterNumber (char[16])
Type (char[25])
Readings:
MeterID (int)
Date (datetime)
Value (numeric(18,6))
I need to get the last reading (and its date) from a given period for each meter, as well as the meter number. I managed to do this in T-SQL, although I'm not particularly pleased with the way I did it using this query:
select distinct
cfg.MeterNumber,
(select top 1 r.Date from Readings as r where r.Date between #startdate and #endDate and r.MeterID = cfg.MeterID order by r.Date desc) as Date,
(select top 1 r.Value from Readings as r where r.Date between #startdate and #endDate and r.MeterID = cfg.MeterID order by r.Date desc) as Value
from
MeterConfig cfg, Readings r1
where cfg.MeterID = r1.MeterID and r1.Date between #startdate and #endDate;
How can I do this more efficiently?
WITH CTE AS (
SELECT mc.MeterID, Date, Value, ROW_NUMBER() OVER (PARTITION BY mc.MeterID ORDER BY Date DESC) as Rank
FROM MeterConfig mc
INNER JOIN Readings rd
ON mc.MeterID = rd.MeterID
WHERE rd.Date BETWEEN #startdate AND #endDate)
SELECT * FROM CTE WHERE Rank = 1
Assuming the dates in Readings are unique (ic include a timestamp), following should be equivalent to your query.
SELECT DISTINCT cfg.MeterNumber
, r1.Date
, r1.Value
FROM MeterConfig cfg
INNER JOIN Readings r1 ON cfg.MeterID = r1.MeterID
INNER JOIN (
SELECT date = MAX(r.Date)
FROM Readings r
WHERE r.Date BETWEEN #StartDate AND #EndDate
) r2 On r2.date = r1.date