Conditional list.generate (like a nested if)

HI HotChilli

I have gotten it to work now, thnak you for looking.

The solution was to change the if condition to measure against a number, so I changed it to look at the actual position column based on if it was <>1 my code is below for anyone interested, I did have to change other parts of the code to reflect that change also.

"= List.Generate(
()=>[
CR = 0,
NR = 1,
EX = -1,
CRRotaName = #"Rota_Data (2)"{CR}[ROTA],
NRRotaName = #"Rota_Data (2)"{NR}[ROTA],
CRTime = #"Rota_Data (2)"{CR}[TimeStart],
NRTime = #"Rota_Data (2)"{NR}[TimeStart],
ActualPosition = 0
],

each [CR] < List.Max(#"Rota_Data (2)"[Index]),

each
if
[ActualPosition] <>1

then [
CR = [CR] +1,
NR = [NR] +1,
EX = [EX] +1,
CRRotaName = #"Rota_Data (2)"{CR}[ROTA],
NRRotaName = #"Rota_Data (2)"{NR}[ROTA],
CRTime = [CRTime] + #"Rota_Data (2)"{EX}[Actual Duration],
NRTime = #"Rota_Data (2)"{NR}[TimeStart],
ActualPosition = [ActualPosition]+1
]

else [
CR = [CR] +1, //Not sure if these should be incremental increases or each
NR = [NR] +1,
EX = [EX] +1,
CRRotaName = #"Rota_Data (2)"{CR}[ROTA],
NRRotaName = #"Rota_Data (2)"{NR}[ROTA],
CRTime = [NRTime],
NRTime = #"Rota_Data (2)"{NR}[TimeStart],
ActualPosition = [ActualPosition]+1
]

)"

I've got a custom column with the duration (TotDuration) and then another custom column with the recalculated starttime of each session:

Table.AddColumn(#"Changed Type", "TotDuration", each List.Sum(Table.SelectRows(
                #"Changed Type",
                (row) =>
                    row[ROTA] = [ROTA]
                    and
                    row[Index] < [Index] 
            )
            [Actual Duration]))

and

if [TotDuration] = null then [TimeStart] else [TimeStart] + [TotDuration]

let me know how you get on.