MySQL---> Write the inner join query for the following groups of tables.

PLEASE EXPLAIN!

a. Advisor, student, instructor

b. Takes, section, student

create table instructor (ID numeric(5,0), name varchar(20) not null, dept_name varchar(20), salary numeric(8,2) check (salary > 29000), primary key (ID), foreign key (dept_name) references department (dept_name) on delete set null );

create table section (course_id numeric(8,0), sec_id numeric(8,0), semester varchar(6) check (semester in ('Fall', 'Winter', 'Spring', 'Summer')), year numeric(4,0) check (year > 1701 and year < 2100), building varchar(15), room_number numeric(7,0), time_slot_id varchar(4), primary key (course_id, sec_id, semester, year), foreign key (course_id) references course (course_id) on delete cascade, foreign key (building, room_number) references classroom (building, room_number) on delete set null );

create table student (ID numeric(5,0), name varchar(20) not null, dept_name varchar(20), tot_cred numeric(3,0) check (tot_cred >= 0), primary key (ID), foreign key (dept_name) references department (dept_name) on delete set null );

create table takes (ID numeric(5,0), course_id numeric(8,0), sec_id numeric(8,0), semester varchar(6), year numeric(4,0), grade varchar(2), primary key (ID, course_id, sec_id, semester, year), foreign key (course_id, sec_id, semester, year) references section (course_id, sec_id, semester, year) on delete cascade, foreign key (ID) references student (ID) on delete cascade );

create table advisor (s_ID numeric(5,0), i_ID numeric(5,0), primary key (s_ID), foreign key (i_ID) references instructor (ID) on delete set null, foreign key (s_ID) references student (ID) on delete cascade );