You can add, alter, and delete column defaults in Sybase Central using the Value tab of the column properties sheet.
Displaying the property sheet for a column
Connect to the database.
Open the Tables folder for that database.
Double-click the table holding the column you want to change.
In the right pane, click the Columns tab.
Select the desired column.
Choose File > Properties.
The property sheet of the column appears.
When you create a new column, some attributes are hidden
until you select Data Type or Value and click the ellipses.
