Using column domain

If you create ERD for serious database development purpose, you may need to specify a lot of details for entity columns in addition to their names. For example, the type, length, default value, etc.

To specify these properties can be a time consuming task. Visual Paradigm supports the use of column domain in re-using specification details between columns.

Each domain is a named set of property values that can be re-used by a column. You can create a domain for commonly entered values such as type, length and default value, and re-use these setting in other columns when needed. This saves you time in creating similar columns as well as to keep your data model consistent.

Defining a column domain

You can define a column domain from the Column Specification window of any column. To define a column domain:

1. Right click on any column and select Open Specification… from the popup menu.
2. Click on the drop down menu of the Domain row and select Configure Domains… from the drop-down menu.
   
3. In the Configure Column Domains window, click Add….
4. Enter the name of the domain.
   
5. Specify the properties. The properties you specified will be re-used by columns that use this domain.
   
6. Click OK to confirm.

Using a column domain

To use a column domain:

1. Open the specification of the column to which you want use a domain. You can open column specification by right clicking on that column and selecting Open Specification… from the popup menu.
2. Click on the drop down menu of the Domain row.
3. Select the domain to use from the drop-down menu.
   
4. Click OK to confirm. By doing so the column will be updated to apply the property values specified in the domain.