Remove rows based on same AND other column

The Source line, where you see the Base64 conversion, is what you get when you paste the data into a table in PowerBI/PowerQuery. You should replace the Source line with your own source. You can read the M code documentation for the Binary.FromText function, but that Base64 argument merely determines the type of Binary encoding to be used.

And either you didn't run the code, or I misunderstood your before and after.

Source Step:

And you wrote: remove rows 1,4 and keep 2,3,5,6,7

After running code:

Did I misunderstand what you wanted?  Or did you not run the code to see what it did?

If I misunderstood, what rows did you wish to keep? As the code I provided clearly keeps 2,3,5,6 and 7

Hi FabvE ,
Thanks for ronrsnfld reply.
You can try the following code

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("ndBRC4IwEAfwr3LsOVCnlj1FBX6AICrEB7WjjXSTbeLXbwwJs0HQw8F2cL/9b0VBIrIiR4WVwRPqXgqNtrG3dWGVgaqWg4F2EA3b2V4WRGFAQ5rY81mjiki5Kgh9E7lUnb1c3ThvGNxR84cArqFGY1BNCJ0j1CGxL8dPKJ5DsYMSH3RwEAoYedvCiNAhmslI50bijHS50c1WzjUDqaCX6jmNbr+fX/+zB/34kNRBGx/kz0GzRY7yBQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Unique ID" = _t, Operation = _t, #"From ID" = _t, #"Form Name" = _t, Timestamp = _t, User = _t]),
    AddFormID = Table.AddColumn(Source, "FormID", each if [Operation] = "CreateForm" then [From ID] else null),
    FillDownFormID = Table.FillDown(AddFormID,{"FormID"}),
    FilterCreateResponse = Table.SelectRows(FillDownFormID, each [Operation] = "CreateResponse"),
    AddCustom = Table.AddColumn(FilterCreateResponse, "HasCorrespondingForm", each List.Contains(FillDownFormID[FormID], [From ID])),
    RemoveInvalidResponses = Table.SelectRows(AddCustom, each [HasCorrespondingForm] = true),
    CombineTables = Table.Combine({Table.SelectRows(FillDownFormID, each [Operation] = "CreateForm"), RemoveInvalidResponses}),
    SortByUniqueID = Table.Sort(CombineTables,{{"Unique ID", Order.Ascending}}),
    RemoveHelperColumns = Table.RemoveColumns(SortByUniqueID,{"FormID", "HasCorrespondingForm"})
in
    RemoveHelperColumns

Final output

Best regards,
Albert He

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly

Ok, after many tries and more fails I went with another approach which solved my problem.

I created an addinional query which contained only the created records:

let
Quelle = Table.SelectRows(Auswertung_raw, each [Operation] = "CreateForm")
in
Quelle

I then used Merge queries to do a join between the initial table Auswertung_raw and the CreateForm-Table:

let
Quelle = Table.NestedJoin(Auswertung_raw, {"FormId"}, tblErstellteUmfragen, {"FormId"}, "tblErstellteUmfragen", JoinKind.LeftSemi),
#"Entfernte Duplikate" = Table.Distinct(Quelle, {"RecordId"})
in
#"Entfernte Duplikate"

This gives me a table with all responses which have a corresponding CreateForm + the initial CreateForm-entries.

Nevertheless, thank you all - especially ronrsnfld- for your help and time! 👍