Based on an earlier post on connecting airtable data to Power BI, some folks, including me, have problems reading Airtable fields/columns that have blank/missing values for some records. Based on an note from a user in the early post, I am able to revise the Airtable M Query code from the Airtable support site (https://support.airtable.com/docs/visualizing-airtable-records-in-microsoft-power-bi-power-query). I added the "List_fields"= line near the end of the query. Now the new M Query can read in all columns / fields of an Airtable table even if they have blank/missing values.
Here is the revised M Query. Hope this can be of help to you.
let Pagination = List.Skip( List.Generate( () => [Page_Key = "init", Counter=0], // Start Value
each [Page_Key] <> null, // Condition under which the next execution will happen
each [
Page_Key = try if [Counter]<1 then ""
else
[WebCall][Value][offset] otherwise null, // determine the LastKey for the next execution
WebCall = try if [Counter]<1
then
Json.Document(Web.Contents("https://api.airtable.com",[RelativePath="v0/"&BASE_ID&"/"&TABLE_ID,Headers=[Authorization="Bearer "&PERSONAL_ACCESS_TOKEN]]))
else
Json.Document(Web.Contents("https://api.airtable.com",[RelativePath="v0/"&BASE_ID&"/"&TABLE_ID&"?offset="&[WebCall][Value][offset], Headers=[Authorization="Bearer "&PERSONAL_ACCESS_TOKEN]])),// retrieve results per call
Counter = [Counter]+1// internal counter
],
each [WebCall]
),1),
#"Converted to Table" = Table.FromList(
Pagination, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Expanded Column1" = Table.ExpandRecordColumn(
#"Converted to Table", "Column1", {"Value"}, {"Column1.Value"}),
#"Expanded Column1.Value" = Table.ExpandRecordColumn(
#"Expanded Column1", "Column1.Value", {"records"}, {"Column1.Value.records"}),
#"Expanded Column1.Value.records" = Table.ExpandListColumn(
#"Expanded Column1.Value", "Column1.Value.records"),
#"Expanded Column1.Value.records1" = Table.ExpandRecordColumn(
#"Expanded Column1.Value.records", "Column1.Value.records",
{"id", "fields", "createdTime"},
{"Column1.Value.records.id", "Column1.Value.records.fields", "Column1.Value.records.createdTime"}),
#"Renamed Columns" = Table.RenameColumns(
#"Expanded Column1.Value.records1",{{"Column1.Value.records.id", "_airtableRecordId"},
{"Column1.Value.records.createdTime", "_airtableRecordCreatedAt"},
{"Column1.Value.records.fields", "_airtableRecordFields"}}),
#"Reordered Columns" = Table.ReorderColumns(
#"Renamed Columns",
{"_airtableRecordId", "_airtableRecordCreatedAt", "_airtableRecordFields"}),
List_Fields = Table.ToList(Table.SelectColumns(Table.Distinct(Table.ExpandListColumn(Table.AddColumn(#"Reordered Columns", "Custom", each Record.FieldNames([_airtableRecordFields])), "Custom"), {"Custom"}),{"Custom"})),
#"Expanded Record Fields" = Table.ExpandRecordColumn(
#"Reordered Columns", "_airtableRecordFields", List_Fields)
in
#"Expanded Record Fields"