CREATE TABLE Teachers (last_name VARCHAR, teacher_id VARCHAR)
CREATE TABLE Detention (teacher_id VARCHAR, detention_type_code VARCHAR)

Find the id and last name of the teacher that has the most detentions with detention type code 'AFTER'?
SELECT T1.teacher_id, T2.last_name FROM Detention AS T1 JOIN Teachers AS T2 ON T1.teacher_id = T2.teacher_id WHERE T1.detention_type_code = "AFTER" GROUP BY T1.teacher_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T1"."teacher_id", "T2"."last_name" FROM "Detention" AS "T1" JOIN "Teachers" AS "T2" ON "T1"."teacher_id" = "T2"."teacher_id" WHERE "AFTER" = "T1"."detention_type_code" GROUP BY "T1"."teacher_id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1