I have stuck in Exercise: 66 on the https://www.sql-ex.ru/

2

The result of correct query:

Dt Qty
2003-04-01 00:00:00.000 1
2003-04-02 00:00:00.000 0
2003-04-03 00:00:00.000 0
2003-04-04 00:00:00.000 0
2003-04-05 00:00:00.000 1
2003-04-06 00:00:00.000 0
2003-04-07 00:00:00.000 0