LAG with Dates

[GallegoRIvas]

Hi Probably I am not understanding LAG function, but looks like only works with "int" data types, In my example "FolderDate" is a datetime data type, I am trying to create a SCD Type 2 using LAG and LEAD.

@WITH_LAG= SELECT * ,LAG(FolderDate, 1, 0) OVER(PARTITION BY BUS_STOP_NUMBER ORDER BY FolderDate DESC) AS Valid_From //,LEAD(FolderDate, 1, 0) OVER(PARTITION BY BUS_STOP_NUMBER ORDER BY FolderDate DESC) AS Valid_To FROM @ToInsert ;

This is the error message :

Severity Code Description Project File Line Suppression State

Error E_CSC_USER_LAGLEADDEFAULTINVALIDTYPE: The "default value" argument of LAG or LEAD function has invalid type. Cannot convert int to DateTime?. Description: The "default value" argument of LAG or LEAD function must be of the same or compatible type as the function's result. Resolution: Change the argument so that it is of the expected type.