Built-In Attributes

• Jun 30, 2021
• 3 minutes to read

Built-in attributes allow you to provide detailed mapping information to XPO and thus address any business requirement. The table below lists all the attributes provided by XPO.

Attribute	Description
AggregatedAttribute	Indicates that persistent objects referenced by the target property are aggregated.
AssociationAttribute	Identifies the end of an association that is involved in an object relationship.
ColumnDbDefaultValueAttribute	Applied to persistent class’ fields or properties. Specifies the SQL expression representing the default value of the database column mapped to the target property/field.
ColumnDefaultValueAttribute	Applied to persistent class’ fields or properties. Specifies the default value of the database column mapped to the target property/field.
CustomAttribute	Specifies a custom attribute for a class or a class member.
DbTypeAttribute	Specifies the database type of the column that a property is mapped to.
DefaultMembersPersistence	Lists the values that determine which members are implied as persistent by default.
DeferredDeletionAttribute	Enables deferred object deletion.
DelayedAttribute	Indicates that the property’s value should not be loaded when a persistent object is being loaded. The property will be loaded the first time it is accessed.
DisplayNameAttribute	Specifies the member’s display name.
ExplicitLoadingAttribute	Specifies that the information used to retrieve persistent objects that are referenced by the current property, is included in a query used to load this property.
FetchOnlyAttribute	Applied to persistent properties and fields. When applied, specifies that the target property or field value can be loaded from the database but should not be saved (should not be included in the INSERT and UPDATE SQL statements).
IndexedAttribute	Indicates that a property or field affects index creation.
IndicesAttribute	Specifies the properties that affect the creation of non-unique database indices.
KeyAttribute	Indicates that a property or a field is a key.
MapInheritanceAttribute	Specifies the type of object-relational inheritance mapping for the class.
MemberDesignTimeVisibilityAttribute	Specifies whether a property or class is visible at design time.
NoForeignKeyAttribute	Disables automatic creation of the FOREIGN KEY constraints.
NonPersistentAttribute	Indicates that a class, property, or field will not be stored in a persistent data store.
NullableAttribute	Applies to persistent class’ fields or properties. Specifies if a nullable column should be created when updating the database schema for the target property/field.
NullableBehaviorAttribute	Applied to persistent classes. Specifies if nullable columns should be created when updating the database schema for the target class.
NullValueAttribute	Associates a constant with the null value of a property or a field of a simple type.
OptimisticLockingAttribute	Specifies that a persistent object’s state can be locked during a session.
PersistentAliasAttribute	Indicates that a property is not persistent and its value is calculated based upon the values of a specific field(s).
PersistentAttribute	Indicates that a property, field or class will be stored in a persistent data store and specifies the target column or table name.
SizeAttribute	Specifies the maximum number of characters that can be stored in a column which is created to store the data of a property or field.
ValueConverterAttribute	Specifies that a property is made persistent using a Value Converter.