Condition If Date column is empty against Id

Hi Junaid11 ,

Aside from merging queries like jsaunders_zero9  has suggested is using the Table.Group function in Power Query.

• First a custom column is created that will return 1 if [ID]  is null.
• Second, the whole table is grouped by [ID] so that transforms the current table into two columns: [ID] and another column with tables that contains all the records prior to grouping.
  
• Third, create a custom column that will sum column created in the first step per row ID.
• Last, expand the column of tables created in the second step to show just the date.
  

   

Here 's a sample M Script to be pasted on a blank query:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcjRU0lEyMtY3MNI3MjAyVIrVgYoZWugbGILEDCBiRkAxBQQTKGdgCZWOBQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Date = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"ID", type text}, {"Date", type date}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "BlankDate", each if [Date] = null then 1 else null, Int64.Type),
    #"Grouped Rows" = Table.Group(#"Added Custom", {"ID"}, {{"Count", each _, type table [ID=nullable text, Date=nullable date, BlankDate=number]}}),
    #"Added Custom1" = Table.AddColumn(#"Grouped Rows", "Ready/Not Ready", each if List.Sum([Count][BlankDate]) <> null then "Not Ready" else "Ready", type text),
    #"Expanded Count" = Table.ExpandTableColumn(#"Added Custom1", "Count", {"Date"}, {"Date"})
in
    #"Expanded Count"

Alternatively, you can create a calculated column using DAX that will scan the table and return whether there is a blank date per row id.

Ready/Not Ready = 
VAR CountOfBlank =
    CALCULATE (
        COUNTBLANK ( 'Table (3)'[Date] ),
        ALLEXCEPT ( 'Table (3)', 'Table (3)'[ID] )
    )
RETURN
   IF ( CountOfBlank > 0, "Not Ready", "Ready" )