Definition of an Associative Table
An associative table is a non-prime table whose primary key columns are all foreign keys.
Because associative tables model pure relationships rather than entities, the rows of an associative table do not represent entities. Instead, they describe the relationships among the entities the table represents.
Always define all your prime tables before defining any associative tables.
The following associative table, table_a-b, associates prime table entity table_a with prime table entity table_b:
|
table_a-b |
|
|
a_Key |
b_Key |
|
PK |
|
|
FK |
FK |
|
A1 |
B1 |
|
A2 |
B5 |
|
A3 |
B2 |