Working with Schemas

Creating a Schema

The following basic steps are required to create a schema (some steps are optional; some may be done in an alternate order to achieve the same result):

• Use the FdoFeatureSchema::Create(“SchemaName”, “FeatureSchema Description”) method to create a schema.
• Use the FdoFeatureSchema::GetClasses() method to return a class collection.
• Use the FdoClass::Create(“className”, “classDescription”) or FdoFeatureClass::Create(“className”, “classDescription”) method to create FdoClass or FdoFeatureClass type objects.
• Use the FdoClassCollection::Add(class) method to add FdoClass or FdoFeatureClass objects to the class collection.
• Use the FdoGeometricPropertyDefinition::Create(“name”, “Description”) method to create FdoGeometryProperty.
• Use the FdoDataPropertyDefinition::Create(“name”, “Description”) method to create FdoDataProperty.
• Use the FdoObjectPropertyDefinition::Create(“name”, “Description”) method to create FdoObjectProperty.
• Use the FdoClassDefinition::GetProperties() and Add(property) methods to add property to class definition.
• Use the FdoIApplySchemaCommand::SetFeatureSchema(feature schema) method to set the schema object for the IFdoApplySchemaCommand.
• Use the FdoAssociationPropertydefinition class to represent the association between two classes. The class of the associated class must already be defined in the feature schema and cannot be abstract.
• Use the FdoIApplySchemaCommand::Execute() method to execute changes to the feature schema.

For an example of schema creation, see Example: Creating a Feature Schema.

Use the FdoClassDefinition::GetIdentityProperties() and Add(Property Object) methods to set the property as FdoClass or FdoFeatureClass Identifier. FDO allows multiple Identifiers for both types of classes, although Identifiers have slight differences in both cases.