calculate time difference of consecutive row dates in SQL - sql

Hello I am trying to calculate the time difference of 2 consecutive rows for Date (either in hours or Days), as attached in the image
Highlighted in Yellow is the result I want which is basically the difference of the date in that row and 1 above.
How can we achieve it in the SQL? Attached is my complex code which has the rest of the fields in it
with cte
as
(
select m.voucher_no, CONVERT(VARCHAR(30),CONVERT(datetime, f.action_Date, 109),100) as action_date,f.col1_Value,f.col3_value,f.col4_value,f.comments,f.distr_user,f.wf_status,f.action_code,f.wf_user_id
from attdetailmap m
LEFT JOIN awftaskfin f ON f.oid = m.oid and f.client ='PC'
where f.action_Date !='' and action_date between '$?datef' and '$?datet'
),
.*select *, ROW_NUMBER() OVER(PARTITION BY action_Date,distr_user,wf_Status,wf_user_id order by action_Date,distr_user,wf_Status,wf_user_id ) as row_no_1 from cte
cte2 as
(
select *, ROW_NUMBER() OVER(PARTITION BY voucher_no,action_Date,distr_user,wf_Status,wf_user_id order by voucher_no ) as row_no_1 from cte
)
select distinct(v.dim_value) as resid,c.voucher_no,CONVERT(datetime, c.action_Date, 109) as action_Date,c.col4_value,c.comments,c.distr_user,v.description,c.wf_status,c.action_code, c.wf_user_id,v1.description as name,r.rel_value as pay_office,r1.rel_value as site
from cte2 c
LEFT OUTER JOIN aagviuserdetail v ON v.user_id = c.distr_user
LEFT OUTER JOIN aagviuserdetail v1 ON v1.user_id = c.wf_user_id
LEFT OUTER JOIN ahsrelvalue r ON r.resource_id = v.dim_Value and r.rel_Attr_id = 'P1' and r.period_to = '209912'
LEFT OUTER JOIN ahsrelvalue r1 ON r1.resource_id = v.dim_Value and r1.rel_Attr_id = 'Z1' and r1.period_to = '209912'
where c.row_no_1 = '1' and r.rel_value like '$?site1' and voucher_no like '$?trans'
order by voucher_no,action_Date

The key idea is lag(). However, date/time functions vary among databases. So, the idea is:
select t.*,
(date - lag(date) over (partition by transaction_no order by date)) as diff
from t;
I should note that this exact syntax might not work in your database -- because - may not even be defined on date/time values. However, lag() is a standard function and should be available.
For instance, in SQL Server, this would look like:
select t.*,
datediff(second, lag(date) over (partition by transaction_no order by date), date) / (24.0 * 60 * 60) as diff_days
from t;

Related

SQL Optimization: multiplication of two calculated field generated by window functions

Given two time-series tables tbl1(time, b_value) and tbl2(time, u_value).
https://www.db-fiddle.com/f/4qkFJZLkZ3BK2tgN4ycCsj/1
Suppose we want to find the last value of u_value in each day, the daily cumulative sum of b_value on that day, as well as their multiplication, i.e. daily_u_value * b_value_cum_sum.
The following query calculates the desired output:
WITH cte AS (
SELECT
t1.time,
t1.b_value,
t2.u_value * t1.b_value AS bu_value,
last_value(t2.u_value)
OVER
(PARTITION BY DATE_TRUNC('DAY', t1.time) ORDER BY DATE_TRUNC('DAY', t2.time) ) AS daily_u_value
FROM stackoverflow.tbl1 t1
LEFT JOIN stackoverflow.tbl2 t2
ON
t1.time = t2.time
)
SELECT
DATE_TRUNC('DAY', c.time) AS time,
AVG(c.daily_u_value) AS daily_u_value,
SUM( SUM(c.b_value)) OVER (ORDER BY DATE_TRUNC('DAY', c.time) ) as b_value_cum_sum,
AVG(c.daily_u_value) * SUM( SUM(c.b_value) ) OVER (ORDER BY DATE_TRUNC('DAY', c.time) ) as daily_u_value_mul_b_value
FROM cte c
GROUP BY 1
ORDER BY 1 DESC
I was wondering what I can do to optimize this query? Is there any alternative solution that generates the same result?
db filddle demo
from your query: Execution Time: 250.666 ms to my query Execution Time: 205.103 ms
seems there is some progress there. Mainly reduce the time of cast, since I saw your have many times cast from timestamptz to timestamp. I wonder why not just another date column.
I first execute my query then yours, which mean the compare condition is quite fair, since second time execute generally more faster than first time.
alter table tbl1 add column t1_date date;
alter table tbl2 add column t2_date date;
update tbl1 set t1_date = time::date;
update tbl2 set t2_date = time::date;
WITH cte AS (
SELECT
t1.t1_date,
t1.b_value,
t2.u_value * t1.b_value AS bu_value,
last_value(t2.u_value)
OVER
(PARTITION BY t1_date ORDER BY t2_date ) AS daily_u_value
FROM stackoverflow.tbl1 t1
LEFT JOIN stackoverflow.tbl2 t2
ON
t1.time = t2.time
)
SELECT
t1_date,
AVG(c.daily_u_value) AS daily_u_value,
SUM( SUM(c.b_value)) OVER (ORDER BY t1_date ) as b_value_cum_sum,
AVG(c.daily_u_value) * SUM( SUM(c.b_value) ) OVER
(ORDER BY t1_date ) as daily_u_value_mul_b_value
FROM cte c
GROUP BY 1
ORDER BY 1 DESC

SQL Server LEAD function

-- FIRST LOGIN DATE
WITH CTE_FIRST_LOGIN AS
(
SELECT
PLAYER_ID, EVENT_DATE,
ROW_NUMBER() OVER (PARTITION BY PLAYER_ID ORDER BY EVENT_DATE ASC) AS RN
FROM
ACTIVITY
),
-- CONSECUTIVE LOGINS
CTE_CONSEC_PLAYERS AS
(
SELECT
PLAYER_ID,
LEAD(EVENT_DATE,1) OVER (PARTITION BY EVENT_DATE ORDER BY EVENT_DATE) NEXT_DATE
FROM
ACTIVITY A
JOIN
CTE_FIRST_LOGIN C ON A.PLAYER_ID = C.PLAYER_ID
WHERE
NEXT_DATE = DATEADD(DAY, 1, A.EVENT_DATE) AND C.RN = 1
GROUP BY
A.PLAYER_ID
)
-- FRACTION
SELECT
NULLIF(ROUND(1.00 * COUNT(CTE_CONSEC.PLAYER_ID) / COUNT(DISTINCT PLAYER_ID), 2), 0) AS FRACTION
FROM
ACTIVITY
JOIN
CTE_CONSEC_PLAYERS CTE_CONSEC ON CTE_CONSEC.PLAYER_ID = ACTIVITY.PLAYER_ID
I am getting the following error when I run this query.
[42S22] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Invalid column name 'NEXT_DATE'. (207) (SQLExecDirectW)
This is a leetcode medium question 550. Game Play Analysis IV. I wanted to know why it can't identify the column NEXT_DATE here and what am I missing? Thanks!
The problem is in this CTE:
-- CONSECUTIVE LOGINS prep
CTE_CONSEC_PLAYERS AS (
SELECT
PLAYER_ID,
LEAD(EVENT_DATE,1) OVER (PARTITION BY EVENT_DATE ORDER BY EVENT_DATE) NEXT_DATE
FROM ACTIVITY A
JOIN CTE_FIRST_LOGIN C ON A.PLAYER_ID = C.PLAYER_ID
WHERE NEXT_DATE = DATEADD(DAY, 1, A.EVENT_DATE) AND C.RN = 1
GROUP BY A.PLAYER_ID
)
Note that you are creating NEXT_DATE as a column alias in this CTE but also referring to it in the WHERE clause. This is invalid because by SQL clause-ordering rules the NEXT_DATE column alias does not exist until you get to the ORDER BY clause which is the last evaluated clause in a SQL query or subquery. You don't have an ORDER BY clause in this subquery, so technically the NEXT_DATE column alias only exists to [sub]queries that both come after and reference your CTE_CONSEC_PLAYERS CTE.
To fix this you'd probably want two CTEs like this (untested):
-- CONSECUTIVE LOGINS
CTE_CONSEC_PLAYERS_pre AS (
SELECT
PLAYER_ID,
RN,
EVENT_DATE,
LEAD(EVENT_DATE,1) OVER (PARTITION BY EVENT_DATE ORDER BY EVENT_DATE) NEXT_DATE
FROM ACTIVITY A
JOIN CTE_FIRST_LOGIN C ON A.PLAYER_ID = C.PLAYER_ID
)
-- CONSECUTIVE LOGINS
CTE_CONSEC_PLAYERS AS (
SELECT
PLAYER_ID,
MAX(NEXT_DATE) AS NEXT_DATE,
FROM CTE_CONSEC_PLAYERS_pre
WHERE NEXT_DATE = DATEADD(DAY, 1, EVENT_DATE) AND RN = 1
GROUP BY PLAYER_ID
)
You gave every table an alias (for example JOIN CTE_FIRST_LOGIN C has the alias C), and every column access is via the alias. You need to add the correct alias from the correct table to NEXT_DATE.
Your primary issue is that NEXT_DATE is a window function, and therefore cannot be referred to in the WHERE because of SQL's order of operations.
But it seems this query is over-complicated.
The problem to be solved appears to be: how many players logged in the day after they first logged in, as a percentage of all players.
This can be done in a single pass (no joins), by using multiple window functions together:
WITH CTE_FIRST_LOGIN AS (
SELECT
PLAYER_ID,
EVENT_DATE,
ROW_NUMBER() OVER (PARTITION BY PLAYER_ID ORDER BY EVENT_DATE) AS RN,
-- if EVENT_DATE is a datetime and can have multiple per day then group by CAST(EVENT_DATE AS date) first
LEAD(EVENT_DATE, 1) OVER (PARTITION BY EVENT_DATE ORDER BY EVENT_DATE) AS NextDate
FROM ACTIVITY
),
BY_PLAYERS AS (
SELECT
c.PLAYER_ID,
SUM(CASE WHEN c.RN = 1 AND c.NextDate = DATEADD(DAY, 1, c.EVENT_DATE)
THEN 1 END) AS IsConsecutive
FROM CTE_FIRST_LOGIN AS c
GROUP BY c.PLAYER_ID
)
SELECT ROUND(
1.00 *
COUNT(c.IsConsecutive) /
NULLIF(COUNT(*), 0)
,2) AS FRACTION
FROM BY_PLAYERS AS c;
You could theoretically merge BY_PLAYERS into the outer query and use COUNT(DISTINCT but splitting them feels cleaner

How to get the validity date range of a price from individual daily prices in SQL

I have some prices for the month of January.
Date,Price
1,100
2,100
3,115
4,120
5,120
6,100
7,100
8,120
9,120
10,120
Now, the o/p I need is a non-overlapping date range for each price.
price,from,To
100,1,2
115,3,3
120,4,5
100,6,7
120,8,10
I need to do this using SQL only.
For now, if I simply group by and take min and max dates, I get the below, which is an overlapping range:
price,from,to
100,1,7
115,3,3
120,4,10
This is a gaps-and-islands problem. The simplest solution is the difference of row numbers:
select price, min(date), max(date)
from (select t.*,
row_number() over (order by date) as seqnum,
row_number() over (partition by price, order by date) as seqnum2
from t
) t
group by price, (seqnum - seqnum2)
order by min(date);
Why this works is a little hard to explain. But if you look at the results of the subquery, you will see how the adjacent rows are identified by the difference in the two values.
SELECT Lag.price,Lag.[date] AS [From], MIN(Lead.[date]-Lag.[date])+Lag.[date] AS [to]
FROM
(
SELECT [date],[Price]
FROM
(
SELECT [date],[Price],LAG(Price) OVER (ORDER BY DATE,Price) AS LagID FROM #table1 A
)B
WHERE CASE WHEN Price <> ISNULL(LagID,1) THEN 1 ELSE 0 END = 1
)Lag
JOIN
(
SELECT [date],[Price]
FROM
(
SELECT [date],Price,LEAD(Price) OVER (ORDER BY DATE,Price) AS LeadID FROM [#table1] A
)B
WHERE CASE WHEN Price <> ISNULL(LeadID,1) THEN 1 ELSE 0 END = 1
)Lead
ON Lag.[Price] = Lead.[Price]
WHERE Lead.[date]-Lag.[date] >= 0
GROUP BY Lag.[date],Lag.[price]
ORDER BY Lag.[date]
Another method using ROWS UNBOUNDED PRECEDING
SELECT price, MIN([date]) AS [from], [end_date] AS [To]
FROM
(
SELECT *, MIN([abc]) OVER (ORDER BY DATE DESC ROWS UNBOUNDED PRECEDING ) end_date
FROM
(
SELECT *, CASE WHEN price = next_price THEN NULL ELSE DATE END AS abc
FROM
(
SELECT a.* , b.[date] AS next_date, b.price AS next_price
FROM #table1 a
LEFT JOIN #table1 b
ON a.[date] = b.[date]-1
)AA
)BB
)CC
GROUP BY price, end_date

SQL - values from two rows into new two rows

I have a query that gives a sum of quantity of items on working days. on weekend and holidays that quantity value and item value is empty.
I would like that on empty days is last known quantity and item.
My query is like this:
`select a.dt,b.zaliha as quantity,b.artikal as item
from
(select to_date('01-01-2017', 'DD-MM-YYYY') + rownum -1 dt
from dual
connect by level <= to_date(sysdate) - to_date('01-01-2017', 'DD-MM-YYYY') + 1
order by 1)a
LEFT OUTER JOIN
(select kolicina,sum(kolicina)over(partition by artikal order by datum_do) as zaliha,datum_do,artikal
from
(select sum(vv.kolicinaulaz-vv.kolicinaizlaz)kolicina,vz.datum as datum_do,vv.artikal
from vlpzaglavlja vz, vlpvarijante vv
where vz.id=vv.vlpzaglavlje
and vz.orgjed='01006'
and vv.skladiste='01006'
and vv.artikal in (3069,6402)
group by vz.datum,vv.artikal
order by vv.artikal,vz.datum asc)
order by artikal,datum_do asc)b
on a.dt=b.datum_do
where a.dt between to_date('12102017','ddmmyyyy') and to_date('16102017','ddmmyyyy')
order by a.dt`
and my output is like this:
and I want this:
In short, if quantity is null use lag(... ignore nulls) and coalesce or nvl:
select dt, item,
nvl(quantity, lag(quantity ignore nulls) over (partition by item order by dt))
from t
order by dt, item
Here is the full query, I cannot test it, but it is something like:
with t as (
select a.dt, b.zaliha as quantity, b.artikal as item
from (
select date '2017-10-10' + rownum - 1 dt
from dual
connect by date '2017-10-10' + rownum - 1 <= date '2017-10-16' ) a
left join (
select kolicina, datum_do, artikal,
sum(kolicina) over(partition by artikal order by datum_do) as zaliha
from (
select sum(vv.kolicinaulaz-vv.kolicinaizlaz) kolicina,
vz.datum as datum_do, vv.artikal
from vlpzaglavlja vz
join vlpvarijante vv on vz.id = vv.vlpzaglavlje
where vz.orgjed = '01006' and vv.skladiste='01006'
and vv.artikal in (3069,6402)
group by vz.datum, vv.artikal)) b
on a.dt = b.datum_do)
select *
from (
select dt, item,
nvl(quantity, lag(quantity ignore nulls)
over (partition by item order by dt)) qty
from t)
where dt >= date '2017-10-12'
order by dt, item
There are several issues in your query, major and minor:
in date generator (subquery a) you are selecting dates from long period, january to september, then joining with main tables and summing data and then selecting only small part. Why not filter dates at first?,
to_date(sysdate). sysdate is already date,
use ansi joins,
do not use order by in subqueries, it has no impact, only last ordering is important,
use date literals when defining dates, it is more readable.

How to self-join table in a way that every record is joined with the "previous" record?

I have a MS SQL table that contains stock data with the following columns: Id, Symbol, Date, Open, High, Low, Close.
I would like to self-join the table, so I can get a day-to-day % change for Close.
I must create a query that will join the table with itself in a way that every record contains also the data from the previous session (be aware, that I cannot use yesterday's date).
My idea is to do something like this:
select * from quotes t1
inner join quotes t2
on t1.symbol = t2.symbol and
t2.date = (select max(date) from quotes where symbol = t1.symbol and date < t1.date)
However I do not know if that's the correct/fastest way. What should I take into account when thinking about performance? (E.g. will putting UNIQUE index on a (Symbol, Date) pair improve performance?)
There will be around 100,000 new records every year in this table. I am using MS SQL Server 2008
One option is to use a recursive cte (if I'm understanding your requirements correctly):
WITH RNCTE AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY symbol ORDER BY date) rn
FROM quotes
),
CTE AS (
SELECT symbol, date, rn, cast(0 as decimal(10,2)) perc, closed
FROM RNCTE
WHERE rn = 1
UNION ALL
SELECT r.symbol, r.date, r.rn, cast(c.closed/r.closed as decimal(10,2)) perc, r.closed
FROM CTE c
JOIN RNCTE r on c.symbol = r.symbol AND c.rn+1 = r.rn
)
SELECT * FROM CTE
ORDER BY symbol, date
SQL Fiddle Demo
If you need a running total for each symbol to use as the percentage change, then easy enough to add an additional column for that amount -- wasn't completely sure what your intentions were, so the above just divides the current closed amount by the previous closed amount.
Something like this w'd work in SQLite:
SELECT ..
FROM quotes t1, quotes t2
WHERE t1.symbol = t2.symbol
AND t1.date < t2.date
GROUP BY t2.ID
HAVING t2.date = MIN(t2.date)
Given SQLite is a simplest of a kind, maybe in MSSQL this will also work with minimal changes.
Index on (symbol, date)
SELECT *
FROM quotes q_curr
CROSS APPLY (
SELECT TOP(1) *
FROM quotes
WHERE symbol = q_curr.symbol
AND date < q_curr.date
ORDER BY date DESC
) q_prev
You do something like this:
with OrderedQuotes as
(
select
row_number() over(order by Symbol, Date) RowNum,
ID,
Symbol,
Date,
Open,
High,
Low,
Close
from Quotes
)
select
a.Symbol,
a.Date,
a.Open,
a.High,
a.Low,
a.Close,
a.Date PrevDate,
a.Open PrevOpen,
a.High PrevHigh,
a.Low PrevLow,
a.Close PrevClose,
b.Close-a.Close/a.Close PctChange
from OrderedQuotes a
join OrderedQuotes b on a.Symbol = b.Symbol and a.RowNum = b.RowNum + 1
If you change the last join to a left join you get a row for the first date for each symbol, not sure if you need that.
You can use option with CTE and ROW_NUMBER ranking function
;WITH cte AS
(
SELECT symbol, date, [Open], [High], [Low], [Close],
ROW_NUMBER() OVER(PARTITION BY symbol ORDER BY date) AS Id
FROM quotes
)
SELECT c1.Id, c1.symbol, c1.date, c1.[Open], c1.[High], c1.[Low], c1.[Close],
ISNULL(c2.[Close] / c1.[Close], 0) AS perc
FROM cte c1 LEFT JOIN cte c2 ON c1.symbol = c2.symbol AND c1.Id = c2.Id + 1
ORDER BY c1.symbol, c1.date
For improving performance(avoiding sorting and RID Lookup) use this index
CREATE INDEX ix_symbol$date_quotes ON quotes(symbol, date) INCLUDE([Open], [High], [Low], [Close])
Simple demo on SQLFiddle
What you had is fine. I don't know if translating the sub-query into the join will help. However, you asked for it, so the way to do it might be to join the table to itself once more.
select *
from quotes t1
inner join quotes t2
on t1.symbol = t2.symbol and t1.date > t2.date
left outer join quotes t3
on t2.symbol = t3.symbol and t2.date > t3.date
where t3.date is null
You could do something like this:
DECLARE #Today DATETIME
SELECT #Today = DATEADD(DAY, 0, DATEDIFF(DAY, 0, CURRENT_TIMESTAMP))
;WITH today AS
(
SELECT Id ,
Symbol ,
Date ,
[OPEN] ,
High ,
LOW ,
[CLOSE],
DATEADD(DAY, -1, Date) AS yesterday
FROM quotes
WHERE date = #today
)
SELECT *
FROM today
LEFT JOIN quotes yesterday ON today.Symbol = yesterday.Symbol
AND today.yesterday = yesterday.Date
That way you limit your "today" results, if that's an option.
EDIT: The CTEs listed as other questions may work well, but I tend to be hesitant to use ROW_NUMBER when dealing with 100K rows or more. If the previous day may not always be yesterday, I tend to prefer to pull out the check for the previous day in its own query then use it for reference:
DECLARE #Today DATETIME, #PreviousDay DATETIME
SELECT #Today = DATEADD(DAY, 0, DATEDIFF(DAY, 0, CURRENT_TIMESTAMP));
SELECT #PreviousDay = MAX(Date) FROM quotes WHERE Date < #Today;
WITH today AS
(
SELECT Id ,
Symbol ,
Date ,
[OPEN] ,
High ,
LOW ,
[CLOSE]
FROM quotes
WHERE date = #today
)
SELECT *
FROM today
LEFT JOIN quotes AS previousday
ON today.Symbol = previousday.Symbol
AND previousday.Date = #PreviousDay