I just went through the exercise questions of the part and found the Exercise 1 may have given a wrong instruction:
Exercise 1: Select the department number and name from the ‘departments_dup’ table and add a third column where you name the department number (‘dept_no’) as ‘dept_info’. If ‘dept_no’ does not have a value, use ‘dept_name’.
The last sentence should be “If ‘dept_name’ does not have a value, use ‘dept_name’.”