Domains make it easier to identify the types of information in your model, assigning domains to columns help you standardize data characteristics for table columns across multiple tables.
Domains are custom datatype definitions that can hold a sub-set of the available values for a datatype. By using domains as the "datatype" of your table columns, you can make the data model more clear and use the same definition in multiple columns across multiple tables.
See also: Objects is a PDM, Domain
This topic holds the following items:
By using the context menu on the Domains node or an existing domain in the Diagram Explorer you can select the New Domain option.
Creating a new Domain
This will show the Domain Properties dialog for a new domain (dialog might be different due to database system differences):
The Domain Properties dialog
Modifying any of the items in the dialog is the same for a new domain as for existing domains.
Each Domain has a name and datatype, the other properties depend on the datatype and the selected database system.
Use the OK button to create the new domain or the Cancel button to go back without creating the new domain.
By double clicking a domain in the Diagram Explorer or using the context menu and selecting Properties from the popup menu, you can start the Domain Properties dialog for existing domains. The dialog that's being shown is the same as for New Domain, but of course, with the details of the selected domain.
After editing a domain and accepting your changes by using the OK button, any tables that are using this domain will be updated as well.
You can delete a domain by using the context menu and selecting Delete Domain from the popup menu. The Diagram Editor will check to see if the domain is in use by any Tables and act accordingly. If the domain isn't being used anywhere, the domain will be delete, if it's in use, you can choose from the following options:
| 1. | Cancel the delete |
| 2. | Set columns that use this domain to a datatype of "unknown" |
| 3. | Use the datatype related properties of the domain for the attributes |
The dialog is similar to the one in a CDM.
Domains will automatically show up in the Table Properties dialog in the Datatype drop down box at the bottom, similar to how this happens in a CDM.