I found some answers to ways to update using over order by, but not anything that solved my issue. In SQL Server 2014, I have a column of DATES (with inconsistent intervals down to the millisecond) and a column of PRICE, and I would like to update the column of OFFSETPRICE with the value of PRICE from 50 rows hence (ordered by DATES). The solutions I found have the over order by in either the query or the subquery, but I think I need it in both. Or maybe I'm making it more complicated than it is.
In this simplified example, if the offset was 3 rows hence then I need to turn this:
DATES, PRICE, OFFSETPRICE
2018-01-01, 5.01, null
2018-01-03, 8.52, null
2018-02-15, 3.17, null
2018-02-24, 4.67, null
2018-03-18, 2.54, null
2018-04-09, 7.37, null
into this:
DATES, PRICE, OFFSETPRICE
2018-01-01, 5.01, 3.17
2018-01-03, 8.52, 4.67
2018-02-15, 3.17, 2.54
2018-02-24, 4.67, 7.37
2018-03-18, 2.54, null
2018-04-09, 7.37, null
This post was helpful, and so far I have this code which works as far as it goes:
select dates, price, row_number() over (order by dates asc) as row_num
from pricetable;
I haven't yet figured out how to point the update value to the future ordered row. Thanks in advance for any assistance.
LEAD is a useful window function for getting values from subsequent rows. (Also, LAG, which looks at preceding rows,) Here's a direct answer to your question:
;WITH cte AS (
SELECT dates, LEAD(price, 2) OVER (ORDER BY dates) AS offsetprice
FROM pricetable
)
UPDATE pricetable SET offsetprice = cte.offsetprice
FROM pricetable
INNER JOIN cte ON pricetable.dates = cte.dates
Since you asked about ROW_NUMBER, the following does the same thing:
;WITH cte AS (
SELECT dates, price, ROW_NUMBER() OVER (ORDER BY dates ASC) AS row_num
FROM pricetable
),
cte2 AS (
SELECT dates, price, (SELECT price FROM cte AS sq_cte WHERE row_num = cte.row_num + 2) AS offsetprice
FROM cte
)
UPDATE pricetable SET offsetprice = cte2.offsetprice
FROM pricetable
INNER JOIN cte2 ON pricetable.dates = cte2.dates
So, you could use ROW_NUMBER to sort the rows and then use that result to select a value 2 rows ahead. LEAD just does that very thing directly.
Related
Good day,
I have a sql table with the following setup:
DataPoints{ DateTime timeStampUtc , bit value}
The points are on a minute interval, and store either a 1(on) or a 0(off).
I need to write a stored procedure to find the points of interest from all the data points.
I have a simplified drawing below:
I need to find the corner points only. Please note that there may be many data points between a value change. For example:
{0,0,0,0,0,0,0,1,1,1,1,0,0,0}
This is my thinking atm (high level)
Select timeStampUtc, Value
From Data Points
Where Value before or value after differs by 1 or -1
I am struggling to convert this concept to sql, and I also have a feeling there is an more elegant mathematical solution that I am not aware off. This must be a common problem in electronics?
I have wrapped the table into a CTE. Then, I am joining every row in the CTE to the next row of itself. Also, I've added a condition that the consequent rows should differ in the value.
This would return you all rows where the value changes.
;WITH CTE AS(
SELECT ROW_NUMBER() OVER(ORDER BY TimeStampUTC) AS id, VALUE, TIMESTAMPUTC
FROM DataPoints
)
SELECT CTE.TimeStampUTC as "Time when the value changes", CTE.id, *
FROM CTE
INNER JOIN CTE as CTE2
ON CTE.id = CTE2.id + 1
AND CTE.Value != CTE2.Value
Here's a working fiddle: http://sqlfiddle.com/#!6/a0ddc/3
If I got it correct, you are looking for something like this:
with cte as (
select * from (values (1,0),(2,0),(3,1),(4,1),(5,0),(6,1),(7,0),(8,0),(9,1)) t(a,b)
)
select
min(a), b
from (
select
a, b, sum(c) over (order by a rows unbounded preceding) grp
from (
select
*, iif(b = lag(b) over (order by a), 0, 1) c
from
cte
) t
) t
group by b, grp
What's wrong with this query? My insert needs to get data from other tables, but when I use select, it gives me error.
Here is the query:
INSERT INTO PAYMENT (
OWNER_HI,
ACCOUNT_ID,
DATE_PAYMENT,
ACCOUNT_VALUE_BEFORE,
CURRENCY,EXCHANGE_RATE,
SUM,
SUM_USD,
DATE_INPUT,
OPERATOR_ID,
DOCUMENT,
INVOICE_ID)
VALUES (
OWNER,
ID,
TODAY,
SALDO,
CURRENCY,
RATE,
50,
(50 * RATE),
TODAY,
386,
'teste sis',
null)
(SELECT TO_CHAR(SYSDATE, 'YYYY-MM-DD') "NOW" FROM DUAL) TODAY
(SELECT VALUE FROM ACCOUNT WHERE ACCOUNT_ID = 386) SALDO
(SELECT CURRENCY_IDCURRENCY_ID FROM CURRENCY_EXCHANGE WHERE rownum=1 ORDER BY CURRENCY_ID DESC) CURRENCY
(SELECT EXCHANGE_RATE FROM CURRENCY_EXCHANGE WHERE rownum=1 ORDER BY CURRENCY_ID DESC) RATE;
And this is the erro:
Erro de SQL: ORA-00933: SQL command not properly ended
00933. 00000 - "SQL command not properly ended"
Perhaps what you meant was something more like
INSERT INTO PAYMENT (
OWNER_HI,
ACCOUNT_ID,
DATE_PAYMENT,
ACCOUNT_VALUE_BEFORE,
CURRENCY,EXCHANGE_RATE,
SUM,
SUM_USD,
DATE_INPUT,
OPERATOR_ID,
DOCUMENT,
INVOICE_ID)
VALUES (
OWNER,
ID,
TO_CHAR(SYSDATE, 'YYYY-MM-DD'),
(SELECT VALUE FROM ACCOUNT WHERE ACCOUNT_ID = 386),
(SELECT CURRENCY_IDCURRENCY_ID FROM CURRENCY_EXCHANGE WHERE rownum=1 ORDER BY CURRENCY_ID DESC),
(SELECT EXCHANGE_RATE FROM CURRENCY_EXCHANGE WHERE rownum=1 ORDER BY CURRENCY_ID DESC),
50,
(50 * RATE),
TODAY,
386,
'teste sis',
null);
Best of luck.
We cannot mix INSERT ... VALUES and INSERT ... SELECT syntax. Choose one or the other. As you need values from other tables, you need INSERT ... SELECT.
There is no relationship between the tables you are querying so use a CROSS JOIN. This won't create a problem as long as you select only one row from each.
SELECT EXCHANGE_RATE FROM CURRENCY_EXCHANGE WHERE rownum=1 ORDER BY CURRENCY_ID DESC doesn't do what you think it does, because ROWNUM is allocated before the sort not afterwards. To get the toppermost currency, use an analytic function like ROW_NUMBER() in a sub-query and filter on that.
I've had to make a couple of guesses because you aren't clear about all the business rules you are implementing but you need something like this:
INSERT INTO PAYMENT (
OWNER_HI,
ACCOUNT_ID,
DATE_PAYMENT,
ACCOUNT_VALUE_BEFORE,
CURRENCY,EXCHANGE_RATE,
SUM,
SUM_USD,
DATE_INPUT,
OPERATOR_ID,
DOCUMENT,
INVOICE_ID)
select user, -- where does OWNER come from??
saldo.account_id,
trunc(sysdate),
SALDO.value,
CURRENCY.CURRENCY_ID ,
CURRENCY.EXCHANGE_RATE ,
50,
(50 * CURRENCY.EXCHANGE_RATE ),
trunc(sysdate),
386,
'teste sis',
null
from ( select CURRENCY_ID,
EXCHANGE_RATE,
row_number() over (order by CURRENCY_ID DESC ) as rn
FROM CURRENCY_EXCHANGE ) currency
cross join
(SELECT * FROM ACCOUNT WHERE ACCOUNT_ID = 386) SALDO
where currency.rn = 1
Note: I've ignored your casting of sysdate to a string (as "TODAY") because storing dates as strings is such incredibly bad practice. I'm hoping you're just doing it as a wait of stripping away the time element from sysdate, which we can also achieve with truncation.
I have table with measurement with column SERIAL_NBR, DATE_TIME, VALUE.
There is a lot of data so when I need them to get the last 48 hours for 2000 devices
Select * from MY_TABLE where [TIME]> = DATEADD (hh, -48, #TimeNow)
takes a very long time.
Is there a way not to receive all the rows for each device, but only the latest entry? Would this speed up the query execution time?
Assuming that there is column named deviceId(change as per your needs), you can use top 1 with ties with window function row_number:
Select top 1 with ties *
from MY_TABLE
where [TIME]> = DATEADD (hh, -48, #TimeNow)
Order by row_number() over (
partition by deviceId
order by Time desc
);
You can simply create Common Table Expression that sorts and groups the entries and then pick the latest one from there.
;WITH numbered
AS ( SELECT [SERIAL_NBR], [TIME], [VALUE], row_nr = ROW_NUMBER() OVER (PARTITION BY [SERIAL_NBR] ORDER BY [TIME] DESC)
FROM MY_TABLE
WHERE [TIME]> = DATEADD (hh, -48, #TimeNow) )
SELECT [SERIAL_NBR], [TIME], [VALUE]
FROM numbered
WHERE row_nr = 1 -- we want the latest record only
Depending on the amount of data and the indexes available this might or might not be faster than Anthony Hancock's answer.
Similar to his answer you might also try the following:
(from MSSQL's point of view, the below query and Anthony's query are pretty much identical and they'll probably end up with the same query plan)
SELECT [SERIAL_NBR] , [TIME], [VALUE]
FROM MY_TABLE AS M
JOIN (SELECT [SERIAL_NBR] , max_time = MAX([TIME])
FROM MY_TABLE
GROUP BY [SERIAL_NBR]) AS L -- latest
ON L.[SERIAL_NBR] = M.[SERIAL_NBR]
AND L.max_time = M.[TIME]
WHERE M.DATE_TIME >= DATEADD(hh,-48,#TimeNow)
Your listed column values and your code don't quite match up so you'll probably have to change this code a little, but it sounds like for each SERIAL_NBR you want the record with the highest DATE_TIME in the last 48 hours. This should achieve that result for you.
SELECT SERIAL_NBR,DATE_TIME,VALUE
FROM MY_TABLE AS M
WHERE M.DATE_TIME >= DATEADD(hh,-48,#TimeNow)
AND M.DATE_TIME = (SELECT MAX(_M.DATE_TIME) FROM MY_TABLE AS _M WHERE M.SERIAL_NBR = _M.SERIAL_NBR)
This will get you details of the latest record per serial number:
Select t.SERIAL_NBR, q.FieldsYouWant
from MY_TABLE t
outer apply
(
selct top 1 t2.FieldsYouWant
from MY_TABLE t2
where t2.SERIAL_NBR = t.SERIAL_NBR
order by t2.[TIME] desc
)q
where t.[TIME]> = DATEADD (hh, -48, #TimeNow)
Also, worth sticking DATEADD (hh, -48, #TimeNow) into a variable rather than calculating inline.
I am trying to find a way to get the last date by location and product a sum was positive. The only way i can think to do it is with a cursor, and if that's the case I may as well just do it in code. Before i go down that route, i was hoping someone may have a better idea?
Table:
Product, Date, Location, Quantity
The scenario is; I find the quantity by location and product at a particular date, if it is negative i need to get the sum and date when the group was last positive.
select
Product,
Location,
SUM(Quantity) Qty,
SUM(Value) Value
from
ProductTransactions PT
where
Date <= #AsAtDate
group by
Product,
Location
i am looking for the last date where the sum of the transactions previous to and including it are positive
Based on your revised question and your comment, here another solution I hope answers your question.
select Product, Location, max(Date) as Date
from (
select a.Product, a.Location, a.Date from ProductTransactions as a
join ProductTransactions as b
on a.Product = b.Product and a.Location = b.Location
where b.Date <= a.Date
group by a.Product, a.Location, a.Date
having sum(b.Value) >= 0
) as T
group by Product, Location
The subquery (table T) produces a list of {product, location, date} rows for which the sum of the values prior (and inclusive) is positive. From that set, we select the last date for each {product, location} pair.
This can be done in a set based way using windowed aggregates in order to construct the running total. Depending on the number of rows in the table this could be a bit slow but you can't really limit the time range going backwards as the last positive date is an unknown quantity.
I've used a CTE for convenience to construct the aggregated data set but converting that to a temp table should be faster. (CTEs get executed each time they are called whereas a temp table will only execute once.)
The basic theory is to construct the running totals for all of the previous days using the OVER clause to partition and order the SUM aggregates. This data set is then used and filtered to the expected date. When a row in that table has a quantity less than zero it is joined back to the aggregate data set for all previous days for that product and location where the quantity was greater than zero.
Since this may return multiple positive date rows the ROW_NUMBER() function is used to order the rows based on the date of the positive quantity day. This is done in descending order so that row number 1 is the most recent positive day. It isn't possible to use a simple MIN() here because the MIN([Date]) may not correspond to the MIN(Quantity).
WITH x AS (
SELECT [Date],
Product,
[Location],
SUM(Quantity) OVER (PARTITION BY Product, [Location] ORDER BY [Date] ASC) AS Quantity,
SUM([Value]) OVER(PARTITION BY Product, [Location] ORDER BY [Date] ASC) AS [Value]
FROM ProductTransactions
WHERE [Date] <= #AsAtDate
)
SELECT [Date], Product, [Location], Quantity, [Value], Positive_date, Positive_date_quantity
FROM (
SELECT x1.[Date], x1.Product, x1.[Location], x1.Quantity, x1.[Value],
x2.[Date] AS Positive_date, x2.[Quantity] AS Positive_date_quantity,
ROW_NUMBER() OVER (PARTITION BY x1.Product, x1.[Location] ORDER BY x2.[Date] DESC) AS Positive_date_row
FROM x AS x1
LEFT JOIN x AS x2 ON x1.Product=x2.Product AND x1.[Location]=x2.[Location]
AND x2.[Date]<x1.[Date] AND x1.Quantity<0 AND x2.Quantity>0
WHERE x1.[Date] = #AsAtDate
) AS y
WHERE Positive_date_row=1
Do you mean that you want to get the last date of positive quantity come to positive in group?
For example, If you are using SQL Server 2012+:
In following scenario, when the date going to 01/03/2017 the summary of quantity come to 1(-10+5+6).
Is it possible the quantity of following date come to negative again?
;WITH tb(Product, Location,[Date],Quantity) AS(
SELECT 'A','B',CONVERT(DATETIME,'01/01/2017'),-10 UNION ALL
SELECT 'A','B','01/02/2017',5 UNION ALL
SELECT 'A','B','01/03/2017',6 UNION ALL
SELECT 'A','B','01/04/2017',2
)
SELECT t.Product,t.Location,SUM(t.Quantity) AS Qty,MIN(CASE WHEN t.CurrentSum>0 THEN t.Date ELSE NULL END ) AS LastPositiveDate
FROM (
SELECT *,SUM(tb.Quantity)OVER(ORDER BY [Date]) AS CurrentSum FROM tb
) AS t GROUP BY t.Product,t.Location
Product Location Qty LastPositiveDate
------- -------- ----------- -----------------------
A B 3 2017-01-03 00:00:00.000
I have tables that record when certain items were sent or returned to a particular location, and I want to work out the intervals between each time a particular item is returned.
Sample data:
Item ReturnDate:
Item1, 20120101
Item1, 20120201
Item1, 20120301
Item2, 20120401
Item2, 20120601
So in this case, we can see that the there was a month gap until Item 1 was returned the first time, and another month before it was returned the second time. Item 2 came back after 2 months.
My starting point is:
Select r1.Item, r1.ReturnDate, r2.Item, r2.ReturnDate, DateDiff(m, r1.ReturnDate, r2.ReturnDate)
from Returns r1
inner join Returns r2 on r2.VehicleNo = r1.VehicleNo
However, in the this sample, each item is compared to every other instance where it has been returned - and not just the next one. So I need to limit this query so it will only compare adjacent returns.
One solution is to tag each return with an count (of the number of times that item has been returned):
Item ReturnDate, ReturnNo:
Item1, 20120101, 1
Item1, 20120201, 2
Item1, 20120301, 3
Item2, 20120401, 1
Item2, 20120601, 2
This would enable me to use the following T-SQL (or similar):
Select r1.Item, r1.ReturnDate, r2.Item, r2.ReturnDate, DateDiff(m, r1.ReturnDate, r2.ReturnDate)
from Returns r1
inner join Returns r2 on r2.VehicleNo = r1.VehicleNo
and (r1.ReturnNo + 1 = r2.ReturnNo)
My first question is whether the is a sensible/optimal approach or whether there is a better approach?
Secondly, what is the easiest/slickest means of calculating the ReturnNo?
If you are using SQL Server 2005+, use ROW_NUMBER() to do exactly what you want:
WITH RankedReturn AS
(
SELECT Item, ReturnDate,
ROW_NUMBER() OVER (PARTITION BY Item ORDER BY ReturnDate DESC) AS ReturnNo
FROM Returns
)
SELECT * FROM RankedReturn
Obviously, now that you have your CTE you can put whatever you need in the outer SELECT. I would use an OUTER APPLY for this:
WITH RankedReturn AS
(
SELECT Item, ReturnDate,
ROW_NUMBER() OVER (PARTITION BY Item ORDER BY ReturnDate DESC) AS ReturnNo
FROM Returns
)
SELECT rOuter.Item, rOuter.ReturnDate, DATEDIFF(month, prev.PrevDate, ReturnDate) AS Months
FROM RankedReturn rOuter
OUTER APPLY
(
SELECT ReturnDate AS PrevDate
FROM RankedReturn rInner
WHERE rOuter.Item = rInner.Item AND rOuter.ReturnNo = rInner.ReturnNo - 1
) prev
Oops, and the SQL Fiddle is here.
Edited because the month difference calculation was backwards; fixed now
Easiest way of calculating the ReturnNo would be to use OVER:
SELECT [Item], [ReturnDate],
ROW_NUMBER() OVER (PARTITION BY [Item] ORDER BY [ReturnDate]) AS ReturnNumber
FROM Returns
http://sqlfiddle.com/#!3/e18ad/1/0
You could also attempt to make use of the techniques for calculating a running total to work out the difference between two rows.
This is how I would do it:
select itemNo,
dt,
DATEDIFF(day, previousDt, dt) as daysSince
from (select itemNo,
dt,
(select top 1 dt from testTable where itemNo = outerTbl.itemNo and dt < outerTbl.dt order by dt desc) as previousDt
from testTable as outerTbl
) as x
... and here's a bit of setup code for anybody else testing a solution to this
create table testTable(
itemNo nvarchar(20),
dt datetime)
go
insert into testTable values('Item1', '2012-01-01');
insert into testTable values('Item1', '2012-02-01');
insert into testTable values('Item1', '2012-03-01');
insert into testTable values('Item2', '2012-04-01');
insert into testTable values('Item2', '2012-05-01');
go