For exmple i have two tables
A
create table teachers(
id number(4) primary key,
name varchar(20)
);
B
create table students(
id number(4) primary key,
name varchar(20)
);
and a third table
AB
create table Teacher_Student(
T_Id number(4),
S_Id number(4)
);
and their relationship
alter table teacher_student
add constraint s_t_pk Primary key(T_Id, S_Id);
Is this relationship is created correctly? and what would be the insertion query if i want to add a new student or a teacher.
Suggestion: also add referential integrity constraints:
alter table teacher_student
add constraint s_t_fk_t foreign key (T_Id)
references teachers (id)
on delete cascade
on update cascade;
alter table teacher_student
add constraint s_t_fk_s foreign key (S_Id)
references students (id)
on delete cascade
on update cascade;