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Vampirtc's avatar
Vampirtc
Frequent Visitor
5 years ago
Solved

Problem merging two tables using LEFT Outer join

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 ...
Need Help
  • v-alq-msft's avatar
    v-alq-msft
    5 years ago

    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's avatar
Jimmy801
Community Champion
5 years ago

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