Problem merging two tables using LEFT Outer join

[Vampirtc]

I would like to merge two tables without creating duplicates in first table. Second table has duplicated IDs, which is what I need.

For example, table 1:
ID  Name
1   XX

2   YX

3   YY
Table 2:

ID  Info
2 c
2 a
4 b
Currently it does

1   XX m

2   YX c

2   YX a

3   YY

What I want:

1   XX m

2   YX c a

3   YY

[Vampirtc]

Thank you both that solved the problem.

[v-alq-msft · Accepted solution]

Hi, @Vampirtc 

Based on your description, i created data to reproduce your scenario. The pbix file is attached in the end.

Table1:

Table2:

You may create a new query with the following m codes in 'Advanced Editor'.

let
    Source = Table.NestedJoin(Table1, {"ID"}, Table2, {"ID"}, "Data", JoinKind.LeftOuter),
    Custom1 = Table.TransformColumns(Source,{"Data",each Text.Combine([Info]," "),type text})
in
    Custom1

Result:

Best Regards

Allan

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

[Jimmy801]

Hello @Vampirtc 

the trick here is to no use Table.ExpandTableColumn but use Table.AggregateTableColumn and as a function use Text.Combine.

Table.AggregateTableColumn(Join, "TableB", {{"Info",each Text.Combine(_, " ") , "Info aggregated"}})

 Here the complete code

let
    TableA = let
            Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUXJ0VIrViVYyAjKdnMBMYyDT2VkpNhYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Name = _t]),
            #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", Int64.Type}, {"Name", type text}})
        in
            #"Changed Type",
    TableB = let
            Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUUpUitWBsJLALCMgKxnOSgGzjIGsVDgrTSk2FgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Info = _t]),
            #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", Int64.Type}, {"Info", type text}})
        in
            #"Changed Type",
    Join = Table.NestedJoin
    (
        TableA,
        "ID",
        TableB,
        "ID",
        "TableB",
        JoinKind.LeftOuter
    ),
    #"Aggregated TableB" = Table.AggregateTableColumn(Join, "TableB", {{"Info",each Text.Combine(_, " ") , "Info aggregated"}})
in
    #"Aggregated TableB"

this is the output

Copy paste this code to the advanced editor in a new blank query to see how the solution works.

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