In a one-to-many relationship, each row in the related to

table can be related to many rows in the relating table.

This allows frequently used information to be saved only

once in a table and referenced many times in all other

tables. In a one-to-many relationship between Table A and

Table B, each row in Table A is linked to 0, 1 or many rows

in Table B. The number of rows in Table A is almost always

less than the number of rows in Table B.

example:

authors table

============

author_id (primary key)

lastname

firstname

book_id (foreign key - link to book_id of books table)

books table

===========

book_id (primary key)

title