Get the profession otherwise industries you want in order to explain once the an important secret

To pick one to community, click on the row selector on the desired profession. To select several fields, hold down the fresh Ctrl secret, and click this new row selector for each and every community.

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If you would like your order of the areas inside a simultaneous-community no. 1 the answer to vary from the transaction of these sphere about dining table, mouse click Spiders towards toolbar showing the new Indexes dialog container, right after which reorder the field names to your directory titled PrimaryKey.

Referential stability

Referential integrity are a network regarding rules that Availableness uses so you’re able to make certain dating anywhere between details when you look at the related tables are valid, and that you don’t affect delete or alter relevant data. You can place referential stability when most of the following standards try true:

• Brand new matching profession on number 1 table are a primary secret otherwise keeps another directory.
• The newest relevant fields have the same investigation type. There are two exclusions. An AutoNumber occupation would be about lots career you to definitely have an effective FieldSize assets form of A lot of time Integer, and you can a keen AutoNumber job who has an effective FieldSize assets setting regarding Replication ID might be linked to a variety job who has an effective FieldSize assets form of Duplication ID.
• One another dining tables end up in a comparable Access databases. In the event your dining tables is actually linked dining tables, they must be tables for the Availability format, and you also need to unlock the latest databases in which they are stored to set referential integrity. Referential integrity cannot be implemented to possess linked dining tables off database from inside the most other formats.

• You simply can’t enter into a regard on the overseas key realm of the associated desk that does not exists however key of number 1 dining table. Although not, you could go into good Null really worth on the overseas trick. That it determine that the records is actually not related. Instance, you simply cannot has your order that is assigned to a customer who would perhaps not occur. Yet not, you will get your order which is allotted to not one person by the typing a Null well worth in the CustomerID job.
• You can’t erase a record off an initial table if matching information exist inside the a connected desk. Eg, you simply can’t erase an employee number regarding the “Employees” table when the there are orders allotted to the new staff member about “Orders” table.
• You simply can’t changes an initial secret really worth throughout the priple, you simply can’t transform an employee’s ID about “Employees” desk if the you can find purchases allotted to one to worker from the “Orders” desk.

Cascading updates and deletes

To have dating where referential integrity is actually enforced, you can specify if you prefer Usage of instantly cascade up-date or cascade erase relevant information. For people who lay such solutions, delete boost surgery who always be prevented by referential stability guidelines try enabled. After you remove records or change number 1 secret philosophy within the good number 1 dining table, Availableness helps to make the requisite change so you’re able to associated tables in preserving referential ethics.

For people who click to search for the Cascade Modify Related Sphere view container once you identify a relationship, when you change the primary secret away from accurate documentation however table, Microsoft Accessibility automatically updates an important key to the latest well worth in all associated records. Such as for example, for many who changes a consumer’s ID regarding “Customers” dining table, the new CustomerID profession on the “Orders” dining table is automatically up-to-date each among one user’s instructions so that the relationships isn’t damaged. Accessibility cascades condition instead of showing one content.

If the primary input the main table was an AutoNumber profession, choosing the Cascade Upgrade Associated Areas have a look at box doesn’t have perception because you usually do not replace the worthy of inside an enthusiastic AutoNumber community.