To choose that profession, click on the row selector into desired profession. To select multiple sphere, hold-down the Ctrl trick, and click this new line selector for each industry.

If you prefer the transaction of one’s industries during the a multiple-profession no. 1 key to vary from the transaction of these sphere from the desk, simply click Indexes toward toolbar showing the brand new Spiders dialogue container, immediately after which reorder industry names for the directory titled PrimaryKey.

Referential stability

Referential integrity is a system regarding regulations one to Access spends in order to make certain matchmaking ranging from suggestions from inside the related dining tables was appropriate, and that you do not affect remove otherwise changes relevant research. You can place referential ethics when every following the conditions was true:

• The brand new coordinating career on no. 1 dining table are a first key otherwise provides a new directory.
• The fresh new associated fields have the same study style of logowanie vgl. There are two exclusions. A keen AutoNumber community should be related to several community one provides a FieldSize assets means regarding A lot of time Integer, and you may an AutoNumber occupation who has an effective FieldSize property function away from Replication ID will likely be connected with lots community that a good FieldSize possessions form away from Replication ID.
• Both tables fall into an identical Accessibility databases. Should your dining tables was linked dining tables, they must be tables during the Supply style, while need open new databases in which he’s kept to set referential integrity. Referential stability can’t be enforced having linked dining tables off database when you look at the other types.

• You can’t go into a regard regarding the overseas secret realm of the newest associated desk that does not exist in the main key of one’s first dining table. Yet not, you could go into an effective Null value in the foreign key. So it specifies your records is not related. Like, you can’t provides an order which is allotted to a customer who would perhaps not exist. But not, you can get your order that is assigned to no one from the typing a Null worth throughout the CustomerID job.
• You simply cannot remove a record off a first table in the event the matching details are present inside a connected desk. Such as for example, you simply cannot remove an employee listing from the “Employees” desk if you’ll find instructions allotted to the newest staff member about “Orders” table.
• You simply can’t changes an initial key worth regarding priple, you can not alter a keen employee’s ID from the “Employees” dining table if the you’ll find sales allotted to one to worker regarding the “Orders” dining table.

Flowing position and deletes

Having dating in which referential stability is enforced, you could identify whether you would like Usage of automatically cascade revise otherwise cascade delete related info. For those who put these types of possibilities, delete boost surgery who usually be prevented because of the referential integrity guidelines is let. After you remove info or alter top secret thinking inside the good no. 1 desk, Availableness helps to make the called for change to help you related tables in preserving referential integrity.

For many who mouse click to search for the Cascade Enhance Associated Areas check box once you explain a love, any time which you replace the number 1 secret out-of accurate documentation in the primary desk, Microsoft Supply instantly standing the main the answer to this new worthy of in every relevant records. Such as, for many who alter a customer’s ID on “Customers” desk, the fresh new CustomerID industry about “Orders” table are instantly up-to-date for each certainly one of you to definitely customer’s instructions so that the matchmaking is not broken. Availableness cascades status instead of displaying any content.

In the event the top input an important table is an enthusiastic AutoNumber job, deciding on the Cascade Inform Related Industries evaluate container does not have any feeling since you never change the well worth into the an enthusiastic AutoNumber field.