Microsoft Access

After you've set up multiple tables in your Microsoft Access database, you need a way of telling Access how to bring that information back together again. The first step in this process is to define relationships between your tables. After you've done that, you can create queries, forms, and reports to display information from several tables at once.

A relationship works by matching data in key fields - usually a field with the same name in both tables. In most cases, these matching fields are the primary key from one table, which provides a unique identifier for each record, and a foreign key in the other table. For example, teachers can be associated with the students they're responsible for by creating a relationship between the teacher's table and the student's table using the TeacherID fields.

Having met the criteria above, follow these steps for creating relationships between tables.

1. In the database window view, at the top, click on Tools ---> Relationships

2. Select the Tables you want to link together, by clicking on them and selecting the Add Button.

3. Drag the primary key of the Parent table (Teacher in this case), and drop it into the same field in the Child table (Student in this case.)
   

4. Select Enforce Referential Integrity
   

5. • When the Cascade Update Related Fields check box is set, changing a primary key value in the primary table automatically updates the matching value in all related records.

   • When the Cascade Delete Related Records check box is set, deleting a record in the primary table deletes any related records in the related table.