OLE DB or ODBC error: [Expression.Error] We cannot apply operator .. to types Null and Number..

[Anonymous]

This is what I have typed and it works in power query without errors.

let
StDt = [STARTDATE],
AllDates =
{Number.From([STARTDATE])..Number.From([ENDDATE])},

StofMonthDate =
List.Distinct(
List.Select(
List.InsertRange(
List.Transform(
AllDates,
each Date.StartOfMonth(Date.From(_))
),
0,
{[STARTDATE]}
),
each Number.From(_) >= Number.From(StDt)
)

)
in
StofMonthDate

But when I try to load the data, I get an error:

OLE DB or ODBC error: [Expression.Error] We cannot apply operator .. to types Null and Number..

I removed blanks in [end_date] and [start_date] but gets the same error. Please help

[Vijay_A_Verma · Accepted solution]

The first statement has to be a Source statement. That source should have columns like STARTDATE and ENDDATE.

OR

You will need to allocate some value to STARTDATE and ENDDATE variables. The moment you say [STARTDATE], it expects it to come from a table. 

[Anonymous]

Those are from my table. STARTDATE and ENDDATE are available in the table

[Vijay_A_Verma]

Please post your complete query alongwith Source statement.