CREATE TABLE CLASS (class_code VARCHAR, crs_code VARCHAR)
CREATE TABLE department (dept_name VARCHAR, dept_code VARCHAR)
CREATE TABLE course (dept_code VARCHAR, crs_code VARCHAR)
CREATE TABLE enroll (class_code VARCHAR)

What is the name of the department that has the largest number of students enrolled?
SELECT T4.dept_name FROM CLASS AS T1 JOIN enroll AS T2 ON T1.class_code = T2.class_code JOIN course AS T3 ON T1.crs_code = T3.crs_code JOIN department AS T4 ON T3.dept_code = T4.dept_code GROUP BY T3.dept_code ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T4"."dept_name" FROM "CLASS" AS "T1" JOIN "enroll" AS "T2" ON "T1"."class_code" = "T2"."class_code" JOIN "course" AS "T3" ON "T1"."crs_code" = "T3"."crs_code" JOIN "department" AS "T4" ON "T3"."dept_code" = "T4"."dept_code" GROUP BY "T3"."dept_code" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1