How to extract list from a record field from a list to table

[arnamq]

Hi,

I have a following JSON:

[
  {
    "timestamp": "2019-08-07T09:41:32.000Z",
    "result": [
      {
        "site_name": "x",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 250565.23678795504
      },
      {
        "site_name": "y",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 3889974.5781805683
      }
    ]
  }
]

...and I want to extract the "result" list as a table. I can extract record from the JOSN as:

timestamp	2019-08-07T09:41:32.000Z
result	List

...but I can't expand the "List" as a table.

Kind regards,

Piotr

[Mariusz · Accepted solution]

Hi @arnamq 

Not sure if I understand what you need, but is this what you after?

please see the attached.

Best Regards,
Mariusz

If this post helps, then please consider Accepting it as the solution.

Please feel free to connect with me.

[Mariusz]

Hi @arnamq 

I've attached the file with a solution, all you need to do is follow the query steps.

Best Regards,
Mariusz

If this post helps, then please consider Accepting it as the solution.

Please feel free to connect with me.

[arnamq]

Thank you for a quick response 🙂

One more question: is it possible to do similar transformation without using expliced declaration of the columnt names?

Depending on the query count and names of a result columns may by different.

Kind regards,

Piotr

[Mariusz · Accepted solution]

Hi @arnamq 

Not sure if I understand what you need, but is this what you after?

please see the attached.

Best Regards,
Mariusz

If this post helps, then please consider Accepting it as the solution.

Please feel free to connect with me.

[arnamq]

//Not sure if I understand what you need, but is this what you after?

No, not exacly but we're close. I mean a situation when the result schema is unknown before running the query. We can skip the "timestamp" field hance that it is constant and focus on the "result" list. Once it may be:

[
  {
    "timestamp": "2019-08-07T09:41:32.000Z",
    "result": [
      {
        "site_name": "x",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 250565.23678795504
      },
      {
        "site_name": "y",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 3889974.5781805683
      }
    ]
  }
]

once

[
  {
    "timestamp": "2019-08-07T09:41:32.000Z",
    "result": [
      {
        "site_name": "x",
        "x": 1948.305445666293,
        "z": 250565.23678795504,
        "a": 1948.305445666293,
        "b": 3889974.5781805683
      },
      {
        "site_name": "y",
        "x": 1948.305445666293,
        "z": 3889974.5781805683,
        "a": 1948.305445666293,
        "b": 3889974.5781805683
      }
    ]
  }
]

and another time it may be:

[
  {
    "timestamp": "2019-08-07T09:41:32.000Z",
    "result": [
      {
        "animal" : "frog"
      },
      {
        "animal" : "lion"
      }
    ]
  }
]

 and another time it may be something else 🙂

Kind regards,

Piotr

[Mariusz]

Hi Piotr ( @arnamq )   

Try the attached 

Best Regards,
Mariusz

If this post helps, then please consider Accepting it as the solution.

Please feel free to connect with me.

[arnamq]

Now in the second step ( #"Converted to Table1" = Record.ToTable(Source),) I have: we cannot convert a value of type List to type Record.

I'm using the same JSON source as previously:

[
  {
    "timestamp": "2019-08-07T09:41:32.000Z",
    "result": [
      {
        "site_name": "x",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 250565.23678795504
      },
      {
        "site_name": "y",
        "count_distinct__z": 1948.305445666293,
        "count_distinct__v": 3889974.5781805683
      }
    ]
  }
]

[v-xuding-msft · Accepted solution]

Hi @arnamq ,

I created a sample to implement it. You could follow the steps.

• Convert list to a table >  Then expend the columns

Here is the script.

let
    Source = Json.Document(File.Contents("C:\Users\xueding\Desktop\821632.json")),
    #"Converted to Table" = Table.FromList(Source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
    #"Expanded Column1" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"timestamp", "result"}, {"Column1.timestamp", "Column1.result"}),
    #"Expanded Column1.result" = Table.ExpandListColumn(#"Expanded Column1", "Column1.result"),
    #"Expanded Column1.result1" = Table.ExpandRecordColumn(#"Expanded Column1.result", "Column1.result", {"site_name", "count_distinct__z", "count_distinct__v"}, {"Column1.result.site_name", "Column1.result.count_distinct__z", "Column1.result.count_distinct__v"})
in
    #"Expanded Column1.result1"

I attached the sample that you can try and check if it is what you want.

Edit:

Attach my sample.  (I find I didn't attach it. )

Best Regards,

Xue Ding

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