If a certain value exists in another table for a column then display value

[Adham]

Hello All,

I really do need help with the following. I have got a table with unique ids.

sample_id

2002181226

2002181227

2002181228

2002181229

And another table containing the following columns.

sample_id       phase    Custom

2002181226	Lower	Outstanding
2002181226	Lower	Outstanding
2002181226	Lower	Outstanding
2002181226	Upper	Done
2002181226	Upper	Outstanding
2002181226	Upper	Outstanding
2002181227	Lower	Outstanding
2002181227	Lower	Outstanding
2002181227	Lower	Outstanding
2002181228	Lower	Outstanding
2002181228	Lower	Outstanding
2002181228	Lower	Outstanding
2002181229	Lower	Done
2002181229	Lower	Done
2002181229	Lower	Done

What i want to do is enter a new column in the first table which does the following:

If any row in custom column contains the value 'Outstanding' for Table_2[sample_id] = Table_1[sample_id] then display Outstanding, else display Done. The result should look like this:

sample_id       Result

2002181226	Outstanding
2002181227	Outstanding
2002181228	Outstanding
2002181229	Done

I would really appreciate some help as i have been stuck on this for half a day.

[dax]

Hi @Adham , 

You also could refer to below M code to see whether it work or not.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMDK0MDQyMlOK1UHimqNyLVC5lkqxsQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [sample_id = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"sample_id", Int64.Type}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"sample_id"}, Table.Sort(#"Table (5)", {{"Custom", Order.Descending}}), {"sample_id"}, "Table (5)", JoinKind.LeftOuter),
    #"Added Custom" = Table.AddColumn(#"Merged Queries", "Custom", each [#"Table (5)"][Custom]{0}),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Table (5)"})
in
    #"Removed Columns"

Table (5) is second table.

Best Regards,
Zoe Zhi

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

[ImkeF · Accepted solution]

Hi @Adham 

this can be done with a special merge of both tables like so:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMDK0MDQyMlOK1UHimqNyLVC5lkqxsQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [sample_id = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"sample_id", Int64.Type}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"sample_id"}, Table.Distinct(Table.Sort(Table_2, {{"Custom", Order.Descending}}), {"sample_d"}), {"sample_d"}, "Table_2", JoinKind.LeftOuter),
    #"Expanded Table_2" = Table.ExpandTableColumn(#"Merged Queries", "Table_2", {"Custom"}, {"Custom"})
in
    #"Expanded Table_2"

So you merge the Table_2 to Table_1 on "sample_id" and then tweak the code so that only one row from the Table_2 remains: The one that is the first after that table has been sorted on column "Custom" in descending order.

... attaching link to file

[Adham]

Hello @ImkeF,

Thank you very much for the solution! I really do appreciate your detailed explanation and ofcourse the file attached! The thing is with this data that more and more sample ids are going to be added. So i am thinking wouldn't it be best to:

- start off with table 2, which is from the database

- reference it to another table so that it is automatically updated as the database is updated

- Sort the Custom column in descending order

- Remove Duplicates based on sample id

Then i get my answer. Please do let me know what do you think!

Thank you again!!

[ImkeF]

Hi  @Adham  

not sure I can follow your explanation, but if the second table contains all values from the first table, there is no need for a merge at all. Simply filter the second table like I did in the merge (or a similar way).

A little comment to @dax ' solution: Although it looks pretty similar to mine, it will run much slower on large datasets, as it is not using a primary key for the merge. (an explanation can be found here: https://blog.crossjoin.co.uk/2018/03/16/improving-the-performance-of-aggregation-after-a-merge-in-po...  )

[Adham]

Hello @ImkeF 

Yes the second table does contain all the values from the first table. Thank you very much!