Types of relationships in ms access

Relationships are the established associations between two or more tables. Relationships are based on common fields from more than one table, often involving primary and foreign keys.

A primary key is the field (or fields) that is used to uniquely identify each record in a table.

There are three requirements for a primary key: It cannot be null, it must be unique, and there can be only one defined per table.

How to create a one-to-many relationship in access between tables

You can define a primary key either by creating a primary key index after the table is created, or by using the CONSTRAINT clause in the table declaration, as shown in the examples later in this section. A constraint limits (or constrains) the values that are entered in a field.

A foreign key is a field (or fields) in one table that references the primary key in another table.

The data in the fields from both tables is exactly the same, and the table with the primary key record (the primary table) must have existing records before the table with the foreign key record (the foreign table) has the matching or related reco

how to establish relationships between tables in access

microsoft access table relationships examples