How to show data properly in Office Excel Using Power Query Editor? - excel

Question

I have below JSON output from an API, in Office Excel I am importing data via Web from API.
[{
"level": 1,
"children": [{
"level": 2,
"children": [{
"level": 3,
"name": "Chandni Chowk",
"data": ["Data 1", "Data 2"]
}],
"name": "Delhi",
"data": ["Delhi Area"]
}],
"name": "Country",
"data": ["India", "Bangladesh"]
}]
https://learn.microsoft.com/en-us/powerquery-m/quick-tour-of-the-power-query-m-formula-language
I have above document.
let
Source = Json.Document(Web.Contents("MY API URL GOES HERE")),
AsTable = Table.FromRecords(Source)
----
----
in
#"Renamed Column2"
In the power query editor I have this for now.
As a out put in Excel file I need like this.
Country Delhi Chandni Chowk
India Delhi Area Data 1
Bangladesh Data 2
Can I get this data from this JSON or I need to change my JSON output format which matches power query?

Answer 1

Power Query interprets JSON as a hierarchy of records and lists. My goal is to flatten the JSON into a record like this and then convert it into a table:
Country : {"India", "Bangladesh"}
Delhi : {"Delhi Area"}
Chandni Chowk : {"Data 1", "Data 2"}
At any particular level, we can pull the name and data value using Record.FromList:
Record.FromList({CurrentLevel[data]}, {CurrentLevel[name]})
For the first level, this is
Record.FromList({{"India","Bangladesh"}}, {"Country"})
which corresponds to the first field in the goal record.
At any level, we can navigate to the next level like this:
NextLevel = CurrentLevel[children]{0}
Using these to building blocks, we can now write a custom function Expand to flatten the record:
1 | (R as record) as record =>
2 | let
3 | ThisLevel = Record.FromList({R[data]}, {R[name]}),
4 | CombLevel = if Record.HasFields(R, {"children"})
5 | then Record.Combine({ThisLevel, #Expand(R[children]{0})})
6 | else ThisLevel
7 | in
8 | CombLevel
Line 1: The syntax for defining a function. It takes a record R and returns a record after doing some transformations.
Line 3: How to deal with the current level, as mentioned earlier.
Line 4: Check if the record has another level to expand down to.
Line 5: If it does, then Record.Combine the result of the current level with the result of the next level, where the result of the next level is calculated by navigating to the next level and recursively applying the function we're defining. With three levels this looks like:
Record.Combine({Level1, Record.Combine({Level2, Level3})})
Line 6: Recursion stops when there are no more levels to expand. No more combinations, just the last level is returned.
All that's left is to transform it into the shape we want. Here's what my query looks like using the Expand function we just defined:
let
Source = Json.Document( < JSON Source > ),
ExpandRecord = Expand(Source{0}),
ToTable = Table.FromColumns(
Record.FieldValues(ExpandRecord),
Record.FieldNames(ExpandRecord)
)
in
ToTable
This uses Record.FieldValues and Record.FieldName as arguments in Table.FromColumns.
The step after using the Expand custom function looks like this in the query editor if you select the first list cell:
The final result is what you asked for: