CREATE TABLE Student_Tests_Taken (registration_id VARCHAR, test_result VARCHAR)
CREATE TABLE Student_Course_Enrolment (date_of_enrolment VARCHAR, registration_id VARCHAR)

What are the enrollment dates of all the tests that have result 'Pass'?
SELECT T1.date_of_enrolment FROM Student_Course_Enrolment AS T1 JOIN Student_Tests_Taken AS T2 ON T1.registration_id = T2.registration_id WHERE T2.test_result = "Pass"
SELECT "T1"."date_of_enrolment" FROM "Student_Course_Enrolment" AS "T1" JOIN "Student_Tests_Taken" AS "T2" ON "Pass" = "T2"."test_result" AND "T1"."registration_id" = "T2"."registration_id"