Question: Find the subject ID, subject name, and the corresponding number of available courses for each subject.
Schema: create table courses (subject_id varchar, PRIMARY KEY (subject_id)); create table subjects (subject_name varchar, subject_id varchar, PRIMARY KEY (subject_name))
SQL: select t1.subject_id, t2.subject_name, count(*) from courses as t1 join subjects as t2 on t1.subject_id = t2.subject_id group by t1.subject_id