A set of feature classes and their properties is called a schema. The schema can have properties that are . The constraints determine which objects you can add to a particular feature class. For example, to be added to the Roads feature class, an object must be a line. Properties are like attributes—they are characteristics of all objects in the feature class. For example, a Roads feature class property can specify the number of lanes it has, or its speed limit. The values vary, but all Roads features have a speed limit and a certain number of lanes.
You cannot change the schemas for all data source types, but you can edit the schemas for SDF files. In this lesson, you edit an SDF schema to add a property to the Roads feature class. The new property is constrained, so only certain values are valid for it.
You can specify that only values within a particular range are valid. You can include or exclude each extreme of the range: the lowest possible value and the highest. For example, you can make a range 1 - 100 inclusive. You can specify a range of any value higher than 1 and lower than 100, but not 1 or 100. You can specify any combination.
Edit the SDF schema.
Create a property with these values. The last four fields appear after setting the Constraint Type.