Count rows on date but some values should be kept as BLANK.

[Mackie]

I have two tables. Left is "open_date" table and right is "sales" table.

 

I want to create a line chart which has date as X-axis and count of sales as Y-axis.
But I want plot not to appear before the store opens.

How do I implement the idel chart? Thank you.

Line chart I made:

Real graph I made

Ideal chart I want:

Ideal graph I want

[Anonymous · Accepted solution]

Please find the solution attached.