One problem you are having is you're not creating the view correctly, try this;
Refer:
Joins and aliases[
^]
CREATE VIEW student_registration_details AS
SELECT
s.studid AS "Student id",
s.firstname AS "First name",
s.lastname AS "Last name",
c.coursename AS "Course name",
c.duration AS "Duration",
r.doj AS "Date of joining"
FROM
student AS s
JOIN
registration AS r ON s.studid = r.studid
JOIN
course AS c ON r.courseid = c.courseid;