- Introduction
- Creating a Custom Database Template
- Using a Custom Database Template
- Planning Tables
- Creating Tables in a Database
- Creating a Table by Entering Data
- Creating an Application Part Using a Template
- Importing Data into Tables
- Linking to Data in Tables
- Working with Table Records
- Working with a Table in Design View
- Specifying a Primary Key in Design View
- Planning Table Relationships
- Defining Table Relationships
- Creating and Printing a Table Relationship Report
- Ensuring Referential Integrity
- Identifying Object Dependencies
- Modifying Object Dependencies
This chapter is from the book
This chapter is from the book
This chapter is from the book
Ensuring Referential Integrity
Table relationships must obey standards of referential integrity, a set of rules that control how you can delete or modify data between related tables. Referential integrity in table relationships keeps users from accidentally deleting or changing related data. You can apply referential integrity when: the common field is the primary tableβs primary key; the related fields have the same format; or both tables belong to the same database. If a primary table contains a list of employees and related tables contain additional information about those employees, and an employee quits, his record is removed from the primary table. His records should also be removed in all related tables. Access allows you to change or delete related data, but only if these changes are cascaded through the series of related tables. You can do this by selecting the Cascade Update Related Fields and Cascade Delete Related Records check boxes in the Edit Relationships dialog box.
Ensure Referential Integrity
Click the Database Tools tab.
Click the Relationships button.
Click the join line for the relationship you want to work with.
Click the Edit Relationships button.
Click to select the Enforce Referential Integrity check box to ensure that referential integrity always exists between related tables in the database.
If you want changes to the primary field of the primary table automatically copied to the related field of the related table, click to select the Cascade Update Related Fields check box.
If you want Access to delete records in the related tables whenever records in the primary table are deleted, click to select the Cascade Delete Related Records check box.
Click OK.
)