Datasheet

17. Click the Add button in the Foreign Key Relationships dialog box to add another relationship.

In the Properties window, click the Tables and Columns Specification property and then click

the elipse button for this property to display the Tables and Columns dialog box.

18. In the Tables and Columns dialog box, select the Projects table in the Primary key table combo

box and then click in the empty row under this combo box and select ProjectID in the combo

box that is displayed. In the first row under the Foreign key table column, select ProjectID in the

combo box that is displayed there and then click OK to return to the Foreign Key Relationships

dialog box.

19. Click Close to close the Foreign Key Relationships dialog box. Next, click the Save icon on the

toolbar to save the GroupProjects table. You are prompted with the tables that will be saved in

your database, which are the tables affected by this relationship. Click Yes to proceed.

20. Using Table 1-8, repeat Steps 14 through 19 to create the rest of the foreign key relationships in

your database.

Table 1-8: Foreign Key Relationships

Foreign Key Table Foreign Key Primary Key Table Primary Key

Users ManagerID Users UserID

Users GroupID Groups GroupID

Users RoleID Roles RoleID

TimeSheets UserID Users UserID

TimeSheets ManagerID Users UserID

TimeSheetItems TimeSheetID TimeSheets TimeSheetID

TimeSheetItems ProjectID Projects ProjectID

How It Works

Using Visual Studio 2005, you connect to the SQL Server instance that contains your ProjectTimeTracker

database in the Server Explorer window using a Data Connection. You are then able to use Visual Studio

2005 to create the tables within your database.

During the process of creating your tables, you set the primary key on each table, effectively creating a

clustered index on the table based on the primary key. After all the tables are created, you create the for-

eign key relationships between the tables, joining the foreign key in one table to the primary key in

another table. This causes a relationship to be formed between your tables and enforces the values that

can be inserted into a table containing a foreign key. The table containing a foreign key will not allow

you to insert a value in the foreign key column that does not exist in the primary key column of the

primary table.

Chapter 1

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