PowerBI - Remove Initial Records with 0 values - powerbi

Question

I have a table in PowerBI that looks like this:
Date StoreID Car Sales <Row Num (for explanation only)>
1/1/2017 1 0 1
1/2/2017 1 0 2
1/3/2017 1 0 3
1/4/2017 1 20 4
1/5/2017 1 13 5
1/6/2017 1 0 6
1/7/2017 1 31 7
1/4/2017 2 0 8
1/5/2017 2 0 9
1/6/2017 2 7 10
1/7/2017 2 0 11
1/8/2017 2 10 12
What I am trying to do is create a measure that will calculate Car Sales by day (so on a line chart with Date on the x-axis), but eliminate the rows/records with 0's until the first Date that has a Sales value. In other words, I want to eliminate rows 1, 2, and 3, but not eliminate row #6, because that is a legitimate day where there were no cars sold. I also want to do this for every StoreID, so I want to eliminate rows 8 and 9, but not 11. Is there any way to come up with a measure/column (or other means) that will accomplish this in PowerBI?

Answer 1

You can group by StoreID, and then transform each column with: sort by [Date], then use Table.Skip to remove rows where [Car Sales] is 0. (Sorting by [Date] might not seem necessary, but group by can change ordering.) Then expand out the grouped tables.
let
Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Date", type datetime}, {"StoreID", Int64.Type}, {"Car Sales", Int64.Type}}),
#"Grouped Rows" = Table.Group(#"Changed Type", {"StoreID"}, {{"Grouped", (grouped) => let
#"Sorted Rows" = Table.Sort(grouped,{{"Date", Order.Ascending}}),
SkipNoCarSales = Table.Skip(#"Sorted Rows", each [Car Sales] = 0)
in
SkipNoCarSales, type table}}),
#"Expanded Grouped" = Table.ExpandTableColumn(#"Grouped Rows", "Grouped", {"Car Sales", "Date"}, {"Car Sales", "Date"}),
#"Reordered Columns" = Table.ReorderColumns(#"Expanded Grouped",{"Car Sales", "StoreID", "Date"})
in
#"Reordered Columns"