Columns
Database columns are represented by the 
icon. If there is a constraint set for the column, the column's icon will have an additional symbol. If a column has more than one constraint assigned to it, only the constraint with the highest priority is shown in the column icon. The priority of constraints is described in the table below, starting with the highest priority.
 | This column is used as the table's primary key. |
 | This column has a unique constraint. |
 | This column has a foreign key that references the primary key of a different table. |
 | This column contains XML data. |
 | There is a default value set for this column. For more information, see Default Constraints and Defining a Default Constraint. |
You can view (and change, if applicable) a column's properties in the Properties window after selecting the column in the Online Browser.
Additional information in Design Editor
When you right-click the header of the table design's Column section, you can select a number of additional properties (Default Value, Description, Identity, Increment, and Seed) to be displayed in the design. Select the properties you want to display or select Show all additional columns from the context menu.
