CREATE TABLE student (dept_code VARCHAR)
CREATE TABLE department (dept_name VARCHAR, dept_code VARCHAR)

What is the department name of the students with lowest gpa belongs to?
SELECT T2.dept_name FROM student AS T1 JOIN department AS T2 ON T1.dept_code = T2.dept_code ORDER BY stu_gpa LIMIT 1
SELECT "T2"."dept_name" FROM "student" AS "T1" JOIN "department" AS "T2" ON "T1"."dept_code" = "T2"."dept_code" ORDER BY "stu_gpa" NULLS FIRST LIMIT 1