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Figure 3: Use the Foreign Key Relationships Dialog Box to Manage a Table's Foreign Key Constraints (Click to view full-size image) Next, click the ellipses icon in the "Table and Columns Specifications" row on the right.This will launch the Tables and Columns dialog box, from which we can specify the primary key table and column and the foreign key column from the table as the foreign key column (see Figure 4).If provided, the user's home town, homepage, and signature will appear on each message he has left in the guestbook.In order to capture the guestbook comments, we need to create a database table named .There are number of different ways to accomplish this: table for each user account.This type of relationship is referred to as one-to-one.That is, if a user makes one or more guestbook comments, and then we attempt to delete that user account, the delete will fail unless his guestbook comments are deleted first.
Oftentimes, applications need to store additional user information not included in the Membership framework.
The table illustrates how to store information that shares a one-to-many relationship with user accounts.
Since each user account may have an arbitrary number of associated comments, this relationship is modeled by creating a table to hold the set of comments that includes a column that links back each comment to a particular user. We now need to associate three columns with each user account to store the user's home town, homepage, and signature, which will appear in his guestbook comments.
After defining the primary and foreign key tables and columns, click OK to return to the Foreign Key Relationships dialog box.
Figure 4: Establish a Foreign Key Constraint Between the Tables (Click to view full-size image) At this point the foreign key constraint has been established.