2011

Setting Up Constraints in the Schema Editor
When you create a schema, you can limit the values that are valid for particular
properties. The types of constraints supported by AutoCAD Map 3D are
described in the following table.
Data Table BehaviorDescriptionType of Con-
straint
Any value outside the specified
range generates an error and you
must enter a different value.
Valid values must be
within the range spe-
cified. You can include or
Range
exclude the minimum
and maximum values. For
example, you can specify
1-10 inclusive, and then
1 and 10 are both valid.
Click the down-arrow to display the
list, and then choose one of the
items as a value for the property.
You supply the list entries
that are valid for the
property.
List
If you leave the property value
empty when you close the Data
The value of the property
cannot be empty.
Not null
Table, an error message prompts
you to enter a value.
If you enter a value that is used by
any other feature in this feature
The value of the property
must be unique within
Unique
class, an error message prompts youthe feature class. If you
to change it. You will not see thedefine the property as an
error message until you check in the
feature.
If the table has two columns that
together must be unique (like
auto-generated field, or
if it is defined in the data
store as a key field, it will
have this constraint.
"Lastname" and "Firstname"), a
message appears on each column
involved in the paired uniqueness
constraint.
Setting Up Constraints in the Schema Editor | 599