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NatashaSchuster
Helper II
Helper II

Replicate LAG T-SQL function logic


Hello, 

 

I was hoping to get an answer to this problem both in DAX and M. 

I am trying to replicate LAG T-SQL function below and return number of days since the last order

SELECT
  CustomerID
, SalesOrderID
, CAST(OrderDate as DATE) AS OrderDate
, DATEDIFF(d,LAG(OrderDate) OVER (PARTITION BY CustomerID ORDER BY SalesOrderID), OrderDate) as DaysSinceLastOrder
FROM Sales.SalesOrderHeader;

 

 

We are trying to get here is the number of days since the last order.

e.g. 7/22/2005 to 7/22/2007 is 730 days and 

7/22/2007 to 11/4/2007 is 105 days 

 

CustomerIDSalesOrderIDOrderDateDaysSinceLastOrder
11000437937/22/2005NULL
11000515227/22/2007730
110005741811/4/2007105
11001437677/18/2005NULL
11001514937/20/2007732
11001727736/12/2008328
11002437367/10/2005NULL
11002512387/4/2007724
11002532378/27/200754
11003437017/1/2005NULL
11003513157/9/2007738
110035778311/11/2007125
11004438107/26/2005NULL
11004515957/26/2007730
110045729311/2/200799

 

 

I started putting together a DAX code but it returns total number of days which for the exaple above for the 3 row instead of 105 return  835 (730+105). 

 

 

Spoiler
  = DATEDIFF(
        CALCULATE(MIN(LAGfunction[OrderDate]), ALLEXCEPT(LAGfunction, LAGfunction[CustomerID]) ),
        CALCULATE(MAX(LAGfunction[OrderDate]), ALLEXCEPT(LAGfunction,  LAGfunction[CustomerID], LAGfunction[SalesOrderID]) ),
        DAY 
    )

 

image.png

 

Thank you

 

2 ACCEPTED SOLUTIONS
v-lili6-msft
Community Support
Community Support

hi, @NatashaSchuster

    After my research, you can do these follow my steps as below:

Step1:

use rankx function to add a group rank column

group rank = RANKX(FILTER(LAGfunction,LAGfunction[CustomerID]=EARLIER(LAGfunction[CustomerID])),LAGfunction[SalesOrderID],,ASC)

Step2:

use eralier function to add the result column

Column = DATEDIFF(CALCULATE(MAX(LAGfunction[OrderDate]),FILTER(LAGfunction,LAGfunction[CustomerID]=EARLIER(LAGfunction[CustomerID])&&LAGfunction[group rank]=EARLIER(LAGfunction[group rank])-1)),LAGfunction[OrderDate],DAY)

Result:

1.PNG

 

here is pbix, please try it.

https://www.dropbox.com/s/8ivwqgzxqmk7byg/Replicate%20LAG%20T-SQL%20function%20logic.pbix?dl=0

 

Best Regards,

Lin

Community Support Team _ Lin
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

View solution in original post

Ashish_Mathur
Super User
Super User

Hi,

 

Try this calculated column formula

 

=if(ISBLANK(CALCULATE(MAX(Data[OrderDate]),FILTER(Data,Data[CustomerID]=EARLIER(Data[CustomerID])&&Data[OrderDate]<EARLIER(Data[OrderDate])))),BLANK(),[OrderDate]-CALCULATE(MAX(Data[OrderDate]),FILTER(Data,Data[CustomerID]=EARLIER(Data[CustomerID])&&Data[OrderDate]<EARLIER(Data[OrderDate]))))

 

Hope this helps.

 

Untitled.png


Regards,
Ashish Mathur
http://www.ashishmathur.com
https://www.linkedin.com/in/excelenthusiasts/

View solution in original post

2 REPLIES 2
Ashish_Mathur
Super User
Super User

Hi,

 

Try this calculated column formula

 

=if(ISBLANK(CALCULATE(MAX(Data[OrderDate]),FILTER(Data,Data[CustomerID]=EARLIER(Data[CustomerID])&&Data[OrderDate]<EARLIER(Data[OrderDate])))),BLANK(),[OrderDate]-CALCULATE(MAX(Data[OrderDate]),FILTER(Data,Data[CustomerID]=EARLIER(Data[CustomerID])&&Data[OrderDate]<EARLIER(Data[OrderDate]))))

 

Hope this helps.

 

Untitled.png


Regards,
Ashish Mathur
http://www.ashishmathur.com
https://www.linkedin.com/in/excelenthusiasts/
v-lili6-msft
Community Support
Community Support

hi, @NatashaSchuster

    After my research, you can do these follow my steps as below:

Step1:

use rankx function to add a group rank column

group rank = RANKX(FILTER(LAGfunction,LAGfunction[CustomerID]=EARLIER(LAGfunction[CustomerID])),LAGfunction[SalesOrderID],,ASC)

Step2:

use eralier function to add the result column

Column = DATEDIFF(CALCULATE(MAX(LAGfunction[OrderDate]),FILTER(LAGfunction,LAGfunction[CustomerID]=EARLIER(LAGfunction[CustomerID])&&LAGfunction[group rank]=EARLIER(LAGfunction[group rank])-1)),LAGfunction[OrderDate],DAY)

Result:

1.PNG

 

here is pbix, please try it.

https://www.dropbox.com/s/8ivwqgzxqmk7byg/Replicate%20LAG%20T-SQL%20function%20logic.pbix?dl=0

 

Best Regards,

Lin

Community Support Team _ Lin
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

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