CREATE TABLE Courses (course_id VARCHAR2, course_name VARCHAR2)
CREATE TABLE Student_Course_Enrolment (date_of_enrolment VARCHAR2, course_id VARCHAR2)

What is the date of enrollment of the course named 'Spanish'?
SELECT T2.date_of_enrolment FROM Courses AS T1 JOIN Student_Course_Enrolment AS T2 ON T1.course_id = T2.course_id WHERE T1.course_name = "Spanish"
SELECT "T2"."date_of_enrolment" FROM "Courses" "T1" JOIN "Student_Course_Enrolment" "T2" ON "T1"."course_id" = "T2"."course_id" WHERE "Spanish" = "T1"."course_name"