Working with Database Tables in the Editor Pane

When you select a database table in the Navigator pane, its properties appear in the Editor pane. Each database table contains the following property tabs:

Fields – Add or modify the table's fields, and specify the field's properties (see Figure 3–2).
References – Specify references between tables (see Figure 3–5).

Working with Field Properties

Use the database table's Field tab to specify properties for the database table's fields.

Note:

Some properties may be unavailable, depending on your database type.

To Specify Table Field Properties:

Select a database table in the Navigator pane. The table's property sheet displays in the Editor pane.
Click the Fields tab.

Figure 3-2 Fields Properties

Description of the illustration fields.gif

Use this table to enter information in each field. Use the scroll bar to display all fields on the tab.

Field	Description
Name	Name of the field.
Type	Use the drop-down list to select the field's type. Note: The valid values will vary, depending on the database.
Size	Size of the field.
Sub-Size	Sub-size of the field.
Allows Null	Specify if this field can be null.
Primary Key	Specify whether this field is a primary key for the table.
Identity	Indicates a Sybase, SQL Server or Informix identity field.
Unique	Specify whether the value must be unique within the table.

Note:

Use the scroll bar to display the additional fields

Enter the necessary information for the existing fields, or click Add Field to add a new field.

To remove a field, select the field and click Remove.

Setting a Primary Key for Database Tables

Use this procedure to set primary key(s) for a database table.

Note:

The OracleAS TopLink Mapping Workbench can automatically import primary key information if supported by the JDBC driver.

To Set a Primary Key:

Select a database table in the Navigator pane. Its property sheet appear in the Editor pane.
Click the Fields tab.

Figure 3-3 Setting Primary Key for a Database Table

Description of the illustration fieldspk.gif
Select the Primary Key field(s) for the table.

Working with Reference Properties

References are table properties that contain the foreign key — they may or may not correspond to an actual constraint that exists on the database. The OracleAS TopLink Mapping Workbench uses these references when you define relationship mappings and multiple table associations.

When importing tables from the database, the OracleAS TopLink Mapping Workbench can automatically create references (if the driver supports this), or you can define references from the workbench.

Creating Table References

Use this procedure to create a new table reference.

To Create a New Table Reference:

Select a database table in the Navigator pane. The table's properties display in the Editor pane.
Click the Table Reference tab (see Figure 3–5).
In the Table References area, click the Add button. The New Reference dialog box appears.

Figure 3-4 New Reference

Description of the illustration newref.gif
Use this table to enter information in each field.

Field	Description
Name of New Reference	Name of the reference table. If you leave this field blank, the OracleAS TopLink Mapping Workbench automatically creates a name based on the format: `SOURCETABLE_TARGETTABLE`.
Select the Source Table	Name of the database table. This field is for display only.
Select the Target Table	Use the drop-down list to specify the target table for this reference.
On Database	Specify if you want to create the reference on the database when you create the table. Not all database drivers support this option.

Continue with Creating Field References.

Creating Field References

Use this procedure to create a new field reference.

To Specify Table Reference Properties:

Select a database table in the Navigator pane. The table's properties display in the Editor pane.
Click on Table Reference tab.

Figure 3-5 References Properties

Description of the illustration reftab.gif

Figure 3–5 calls out the following user-interface components:
1. Table References area
2. Key Pairs area
In the Table References area, select a Table Reference (see "Creating Table References").
In the Key Pairs area, click on Add button. The Source and Target fields appear on the tab.
Use the Source Field and Target Field drop-down lists to choose the key pair for this reference.