I was thinking three tables, one for entity A, second for entity B and third for the relationship and describe the total participation in the third table by importing primary keys from first and second table and terming them as not NULL. Am I on right track?
Consider a relation between students and courses, each student must be associated with at least one course (can be more than one too) and each course must be taken by at least one student (can be taken by more than one students too). This would result in a many to many relationship with total participation from both sides.
CREATE TABLE student ( sid INTEGER, age INTEGER, PRIMARY KEY (sid) ) CREATE TABLE COURSE ( cid INTEGER, timings DATETIME, PRIMARY KEY (cid) ) CREATE TABLE TAKES ( sid INTEGER, cid INTEGER, FOREIGN KEY (sid), FOREIGN KEY (cid), instructor CHAR(12), PRIMARY KEY (sid,cid) )