count the number of duplicates

[II1154]

Bonjour je cherche un moyen avec List de trouver le nombre de doublons (nb.if) sans passer par le doublon du tableau sur powerquery, merci d’avance

occurrence	nb.SI
X1	2
X2	4
X3	3
X4	1
X5	1
X6	2
X2	4
X3	3
X9	1
X10	1
X1	2
X12	1
X2	4
X3	3
X6	2
X2	4

[ronrsnfld · Accepted solution]

• Add an Index Column
• Group by occurrence
  • Aggregate by "All Rows"
  • Aggregate by "Count"
• Expand the "All Rows"
• Sort back to original order using the Index column

Another method that may be less efficient is to add a custom column with the formula:

  List.Count(List.Select(#"Changed Type"[occurrence], (li)=> li = [occurrence]))

To duplicate, paste the code below into a blank query:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WijBUitUBUkYQyhhCmUAoUwhlhk2JJYQyNIDSUMoIm1qEAbEA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [occurrence = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"occurrence", type text}}),

    #"Added Custom" = Table.AddColumn(#"Changed Type", "Count", each 
        List.Count(
            List.Select(#"Changed Type"[occurrence], 
                (li)=> li = [occurrence])), Int64.Type)
in
    #"Added Custom"

[II1154]

too bad that with a line in (list.... power query we can't have that, in powerbi in my case it can't work

[Migasuke]

Hi @II1154 ,

This is not possible.
You could duplocicate the table / list and apply Group By. Then merge the original table with group by table to see number of duplicates.
If you can, try solution in DAX instead.

Ce n'est pas possible. Vous pouvez dupliquer le tableau/la liste et appliquer Grouper par. Fusionnez ensuite la table d'origine avec groupe par table pour voir le nombre de doublons. Si vous le pouvez, essayez plutôt la solution dans DAX.