List the id of students who registered some courses and the number of their registered courses?
CREATE TABLE students (student_id VARCHAR); CREATE TABLE student_course_registrations (student_id VARCHAR)
SELECT T1.student_id, COUNT(*) FROM students AS T1 JOIN student_course_registrations AS T2 ON T1.student_id = T2.student_id GROUP BY T1.student_id
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE students (student_id VARCHAR); CREATE TABLE student_course_registrations (student_id VARCHAR) Question: List the id of students who registered some courses and the number of their registered courses? [/INST] SELECT T1.student_id, COUNT(*) FROM students AS T1 JOIN student_course_registrations AS T2 ON T1.student_id = T2.student_id GROUP BY T1.student_id </s>