Inherits from | |
Conforms to | |
Framework | /System/Library/Frameworks/CoreData.framework |
Availability | Available in Mac OS X v10.6 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.h
Returns the type of the receiver.
- (NSAttributeType)expressionResultType
The type of the receiver.
NSExpressionDescription.h
Sets 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.h
Sets 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.h
Last updated: 2009-02-03