I tried running the code included but got an error that the table doesn't exist. How do I fix it?

Set up RI between the sec0819_departmentstable and the sec0819_employeestable. Handle updates using the cascade rule. Then show the effect of this rule by changing the shipping department code in the sec0819_departments table from SHP to ABC.

MY CODE:

select s.Student_ID, s.First_Name, s.Last_Name, s.Major, c.Course_Number, c.Title from Enrollment e join Student s on e.Student_ID = s.Student_ID join Course c on e.Course_No = c.Course_Number where e.Grade = 'A';