Comparisons with NULL
Functions with NULL
COALESCE to the rescue
Instruction
Goood! Things are getting serious now: let's add another table. You will work with the table product and the table advertisement in the next three exercises.
The table advertisement tells us which products have been advertised so far. It also informs us where and when this happened.
Exercise
For each advertisement, show its id, country, start_date and end_date together with the name of the product advertised.
If there is no start_date or no end_date, show 'n/a' instead. If there is no name of the product, show 'no name'. Order the results by the start_date, with the oldest dates shown first. The column names should be: id, country, start_date, end_date, and name.
Stuck? Here's a hint!
It's a quiz. No hints this time.
