Mark rows depending on previous row

[Anonymous]

Hello everyone,

I have currenly the following problem: I have a column A of numbers (which repeat). One of the rows with the same number has the value "1" in column B (all the others have "0"). What I want is to mark every row with the same number after the row with the value 1 with the value 2:

A	B		A	B		A	B	C
1	0		1	0		1	0	0
1	0		1	0		1	0	0
1	1		1	1		1	1	0
1	0		1	2		1	0	2
1	0		1	2		1	0	2
1	0		1	2		1	0	2
2	1		2	1		2	1	0
2	0	"=>"	2	2	or	2	0	2
2	0		2	2		2	0	2
3	0		3	0		3	0	0
3	0		3	0		3	0	0
3	0		3	0		3	0	0
3	0		3	0		3	0	0
3	1		3	1		3	1	0
3	0		3	2		3	0	2

Has anyone any idea?

[Jimmy801 · Accepted solution]

Hello @Anonymous 

you can add a group-function and then with a Table.TransformColumns apply the necessary changes to the table.

Here the complete solution

let
	Source = #table
	(
		{"A","B"},
		{
			{"1","0"},	{"1","0"},	{"1","1"},	{"1","0"},	{"1","0"},	{"1","0"},	{"2","1"},	{"2","0"},	{"2","0"},	{"3","0"},	{"3","0"},	{"3","0"},	{"3","0"},	{"3","1"},	
			{"3","0"}
		}
	),
    Group = Table.Group(Source, {"A"}, {{"AllRowsB", each Table.SelectColumns(_, "B"), type table [A=text, B=text]}}),
	AddColumn = Table.TransformColumns
	(
		Group,
		{
			{
				"AllRowsB",
				each Table.ReplaceValue(Table.FillDown( Table.AddColumn(_,"C",(row)=> if row[B] = "1" then "2" else null), {"C"}), null, "0", Replacer.ReplaceValue, {"C"})
			}
		}
	),
    ExpandedAllRowsB = Table.ExpandTableColumn(AddColumn, "AllRowsB", {"B", "C"}, {"B", "C"})
in
    ExpandedAllRowsB

Copy paste this code to the advanced editor in a new blank query to see how the solution works. If this solution fits your need, copy and past a part of it and implement it in your query

If this post helps or solves your problem, please mark it as solution (to help other users find useful content and to acknowledge the work of users that helped you)
Kudoes are nice too

Have fun

Jimmy

[Greg_Deckler]

Yeah, it seems that you want some variation of Cthulhu. https://community.powerbi.com/t5/Quick-Measures-Gallery/Cthulhu/td-p/509739

You will almost certainly need to add an Index column to your data, otherwise it is impossible to know which row comes before another.