I have a query that is working fine: The query is to find the sum & Avg for the last 3 months and last year. It is working fine, till I got a new request to break the query down to more details by AwardCode.
So how to include that?
I mean for this section
SUM(1.0 * InvolTerm) OVER (ORDER BY Calendar_Date ASC
ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS InvolMov3Mth,
I want to find the last 3 months based on AwardCode.
My original query that is working is
SELECT
Calendar_Date, Mth, NoOfEmp, MaleCount, FemaleCount,
SUM(1.0*InvolTerm) OVER (ORDER BY Calendar_Date ASC
ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS InvolMov3Mth,
SUM(1.0*TotalTerm) OVER (ORDER BY Calendar_Date ASC
ROWS BETWEEN 11 PRECEDING AND CURRENT ROW) AS TermSum12Mth
FROM #X
The result is
But now I need to add another group AwardCode
SELECT
Mth, AwardCode, NoOfEmp, MaleCount, FemaleCount,
SUM(1.0 * InvolTerm) OVER (ORDER BY Calendar_Date ASC
ROWS BETWEEN 2 PRECEDING AND CURRENT ROW) AS InvolMov3Mth,
SUM(1.0 * TotalTerm) OVER (ORDER BY Calendar_Date ASC
ROWS BETWEEN 11 PRECEDING AND CURRENT ROW) AS TermSum12Mth
FROM #X
The result will be like this
You can notice that the sum of InvolMov3Mth & TermSum12Mth for the whole period does not match the query above
I think I found the answer for my question.
I used PARTITION BY AwardCode before ORDER BY
seems to be working.
SUM(1.0*TotalTerm) OVER (PARTITION BY AwardCode ORDER BY Calendar_Date ASC
ROWS BETWEEN 11 PRECEDING AND CURRENT ROW) AS TermSum12Mth,
Yes. "Partition by" will make it work for your requirment
Related
I need the lowest/highest price of stocks for the past n days. The following query works really slow. I would appreciate faster alternative:
SELECT
*,
MIN(Close) OVER (PARTITION BY Ticker ORDER BY PriceDate ROWS BETWEEN 14 PRECEDING AND 1 PRECEDING) AS MinPrice14d,
MAX(Close) OVER (PARTITION BY Ticker ORDER BY PriceDate ROWS BETWEEN 14 PRECEDING AND 1 PRECEDING) AS MaxPrice14d
FROM
(SELECT CompanyID, Ticker, PriceDate, Close
FROM price.PriceHistoryDaily) a
I need the columns specified.
It is trailing, so I need it day by day.
As for period, I will limit it to one year.
Although it doesn't affect the performance, no subquery is needed. So start with the simpler version:
SELECT phd.CompanyID, phd.Ticker, phd.PriceDate, phd.Close,
min(Close) over (partition by Ticker
order by PriceDate
rows between 14 preceding and 1 preceding
) as MinPrice14d,
max(Close) over (partition by Ticker
order by PriceDate
rows between 14 preceding and 1 preceding
) as MaxPrice14d
FROM price.PriceHistoryDaily phd;
Then try adding an index: PriceHistoryDaily(Ticker, PriceDate).
Note: That this returns all rows from PriceHistoryDaily and -- depending on the size of the table -- that might be what is driving the performance.
I am not able to get the last value, rather it is just returning the same value with my code below in snowflake - does anyone have any idea? Is there something glaring wrong?
select MNTH,
sum_cust,
last_value(sum_cust) over (partition by MNTH order by sum_cust desc ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) as sum_cust_last
from block_2;
I think what you actually want is to LAG the value from the previous MNTH:
SELECT MNTH,
sum_cust,
LAG(sum_cust) OVER (ORDER BY MNTH) AS sum_cust_last
FROM block_2;
I actually recommend first_value() rather than last_value() for some technical reasons involving window frames. If you want the last value, order by the month desc and choose the first row:
select MNTH, sum_cust,
first_value(sum_cust) over (order by MNTH desc
rows between current_row AND UNBOUNDED FOLLOWING
) as sum_cust_last
from block_2;
with cte
as
(
SELECT
year(h.orderdate)*100+month(h.orderdate) as yearmonth,
YEAR(h.orderdate) as orderyear,
sum(d.OrderQty*d.UnitPrice) as amount
FROM [AdventureWorks].[Sales].[SalesOrderDetail] d
inner join sales.SalesOrderHeader h
on d.SalesOrderID=h.SalesOrderID
group by
year(h.orderdate)*100+month(h.orderdate),
year(h.orderdate)
)
select
c.*,
last_value(c.amount) over (partition by c.orderyear order by c.yearmonth) as lastvalue,
first_value(c.amount) over (partition by c.orderyear order by c.yearmonth) as firstvalue
from cte c
order by c.yearmonth
I am expecting to see the lastvalue of each year (say december value), similar to the firstvalue of each year (jan value). however, last_value is not working at all. It just returns the same value of that month. What did I do wrong?
Thanks for the help.
Your problem is that the default row range for LAST_VALUE is RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW, so the value you are getting is the current month's value (that being the last value in that range). To get LAST_VALUE to look at all values in the partition you need to expand the range to include the rows after the current row as well. So you need to change your query to:
last_value(c.amount) over (partition by c.orderyear order by c.yearmonth
rows between unbounded preceding and unbounded following) as lastvalue,
I'm running code like this:
SELECT ID, Date, Price,
STDEV(Price) OVER (ORDER BY ID, Date ROWS BETWEEN 30 PRECEDING AND CURRENT ROW) As OneMonths,
STDEV(Price) OVER (ORDER BY ID, Date ROWS BETWEEN 60 PRECEDING AND CURRENT ROW) As TwoMonths,
STDEV(Price) OVER (ORDER BY ID, Date ROWS BETWEEN 90 PRECEDING AND CURRENT ROW) As ThreeMonths
FROM Price_Table
That gives me this result.
In the fiver first row I always have three nulls for the three variances. This makes sense. However, every time the ID changes, I must be getting the preceding ID's prices, because each time the ID changes, I would expect the standard deviation to get reset. So, the first line in orange should be null, I think, and the next one should be zero, because there is no change in price the second day. I tried wrapping the LAG function around the STDEV function and I got an error. I tried the opposite and also got an error.
If you want the value per id, then you need partition by:
SELECT ID, Date, Price,
STDEV(Price) OVER (PARTITION BY ID ORDER BY Date ROWS BETWEEN 30 PRECEDING AND CURRENT ROW) As OneMonths,
STDEV(Price) OVER (PARTITION BY ID ORDER BY Date ROWS BETWEEN 60 PRECEDING AND CURRENT ROW) As TwoMonths,
STDEV(Price) OVER (PARTITION BY ID ORDER BY Date ROWS BETWEEN 90 PRECEDING AND CURRENT ROW) As ThreeMonths
FROM Price_Table;
I am trying to build a view that generates a movable 13-week average over the past year.
My source data includes a date, customer ID, and integer, and basically I want to average the 13 prior values (including the current one), over the previous 52 weeks. When I'm finished, I'd like to have a table with a date, each customer ID, and trailing 13-week average for that customer.
After upgrading Postgres to 9.1, the window functions worked great for this:
SELECT vs.weekending,
cs.slinkcust AS customer,
cs.slinkid AS id,
round(avg(vs.maxattached) OVER (PARTITION BY cs.slinkid ORDER BY vs.weekending DESC ROWS BETWEEN 0 PRECEDING AND 12 FOLLOWING), 2) AS rolling_conc_avg,
round(avg(vs.totsessions) OVER (PARTITION BY cs.slinkid ORDER BY vs.weekending DESC ROWS BETWEEN 0 PRECEDING AND 12 FOLLOWING), 2) AS rolling_sess_avg,
dense_rank() OVER (ORDER BY vs.weekending) AS week_number
FROM cfg_slink cs
JOIN view_statslink vs ON cs.slinkid = vs.id
WHERE vs.weekending >= (now() - '364 days'::interval) AND cs.disabled = 0
GROUP BY vs.weekending, cs.slinkid, vs.maxattached, vs.totsessions
ORDER BY vs.weekending DESC, cs.slinkcust;