To choose one to field, click on the line selector to your need industry. To choose multiple fields, hold down the fresh Ctrl trick, and then click the row selector for every single industry.

If you want the transaction of your sphere when you look at the a multiple-community top the answer to change from the transaction of these fields on the dining table, click Spiders on the toolbar to show the newest Indexes dialogue field, and then reorder industry labels towards the directory titled PrimaryKey.

Referential stability

Referential stability was a system away from statutes one to Accessibility spends so you’re able to ensure that relationship between info when you look at the associated dining tables is legitimate, and you don’t accidentally erase or alter related investigation. You might set referential stability when every after the standards is true:

• The brand new matching industry on number one desk are a primary secret or keeps a special directory.
• Brand new associated fields have a similar analysis form of. There have been two exclusions. An AutoNumber field will likely be related to a variety career one to have an effective FieldSize assets mode out of Much time Integer, and an enthusiastic AutoNumber community who’s a great FieldSize assets form out of Duplication ID will be connected with lots career that a FieldSize property function from Duplication ID.
• Each other tables fall under an identical Accessibility databases. Should your dining tables is actually linked dining tables, they must be dining tables in Accessibility format, while need certainly to open the fresh database in which he or she is held to put referential stability. Referential stability can’t be implemented to have connected tables out-of databases when you look at the almost every other types.

• You can’t enter into an admiration throughout the foreign secret arena of this new related dining table that will not exists however secret of your own no. 1 dining table. But not, you could enter into a Null really worth on the foreign key. It specifies the information are not related. Such as for instance, you simply can’t enjoys your order that’s allotted to a customers that would perhaps not exist. But not, you’ll have your order that is assigned to not one person from the typing a Null worth about CustomerID job.
• You cannot delete accurate documentation off a primary dining table if the matching details are present during the an associated table. Such, you can’t remove a worker number from the “Employees” table if you can find purchases assigned to the fresh staff throughout the “Orders” desk.
• You simply can’t change an initial trick worthy of throughout the priple, you can not alter an employee’s ID regarding “Employees” dining table if you’ll find sales allotted to one staff member on “Orders” desk.

Flowing condition and deletes

Having dating in which referential stability is actually implemented, you could potentially establish whether you need Accessibility instantly cascade up-date or cascade remove relevant information. For individuals who place these types of selection, remove boost functions who usually be prevented by referential integrity rules was let. After you https://datingranking.net/cs/flingster-recenze remove info or changes first secret viewpoints into the a great first table, Availableness makes the called for alter in order to related dining tables to preserve referential stability.

For people who simply click to search for the Cascade Revise Related Fields evaluate package once you identify a love, at any time that you alter the primary key of accurate documentation however dining table, Microsoft Availableness immediately standing the key key to new really worth in every associated information. Such as for example, for those who changes a consumer’s ID from the “Customers” dining table, the latest CustomerID profession on “Orders” table are automatically upgraded for each and every among that owner’s instructions so the dating isn’t broken. Supply cascades condition without demonstrating one message.

Whether your number 1 type in the main table was an AutoNumber industry, deciding on the Cascade Update Related Areas see package has no effect since you never change the value in the an enthusiastic AutoNumber community.