| Inherits from | |
| Conforms to | |
| Framework | /System/Library/Frameworks/CoreData.framework |
| Availability | Available in iOS 3.0 and later. |
| Companion guide | |
| Declared in | NSExpressionDescription.h |
Instances of NSExpressionDescription objects represent a special property description type intended for use with the NSFetchRequest propertiesToFetch method.
An NSExpressionDescription describes a column to be returned from a fetch that may not appear directly as an attribute or relationship on an entity. Examples might include upper(attribute) or max(attribute). You cannot set an NSExpressionDescription object as a property of an entity.
Returns the expression for the receiver.
- (NSExpression *)expression
The expression for the receiver.
NSExpressionDescription.hReturns the type of the receiver.
- (NSAttributeType)expressionResultType
The type of the receiver.
NSExpressionDescription.hSets the expression for the receiver.
- (void)setExpression:(NSExpression *)expression
The expression for the receiver.
This method raises an exception if the receiver’s model has been used by an object graph manager.
NSExpressionDescription.hSets the type of the receiver.
- (void)setExpressionResultType:(NSAttributeType)type
An NSAttributeType constant that specifies the type for the receiver.
This method raises an exception if the receiver’s model has been used by an object graph manager.
NSExpressionDescription.hLast updated: 2009-02-03