# NSFetchRequestExpression An expression that evaluates the result of a fetch request on a managed object context. ``` class NSFetchRequestExpression ``` ## Overview `NSFetchRequestExpression` inherits from , which provides most of the basic behavior. The first argument must be an expression which evaluates to an `NSFetchRequest` object, and the second must be an expression which evaluates to an `NSManagedObjectContext` object. If you simply want the count for the request, the `countOnly` argument should be . ## Topics ### Creating a Fetch Request Expression [`+ expressionForFetch:context:countOnly:`](/documentation/CoreData/NSFetchRequestExpression/expression(forFetch:context:countOnly:)) Returns an expression which will evaluate to the result of executing a fetch request on a context. ### Examining a Fetch Request Expression [`requestExpression`](/documentation/CoreData/NSFetchRequestExpression/requestExpression) The expression for the receiver’s fetch request. [`contextExpression`](/documentation/CoreData/NSFetchRequestExpression/contextExpression) The expression for the receiver’s managed object context. [`countOnlyRequest`](/documentation/CoreData/NSFetchRequestExpression/isCountOnlyRequest) Returns a Boolean value that indicates whether the receiver represents a count-only fetch request. ### Constants [`NSFetchRequestExpressionType`](/documentation/CoreData/NSFetchRequestExpressionType) This constant specifies the fetch request expression type. ## Relationships ### Inherits From [`NSExpression`](/documentation/Foundation/NSExpression) ### Conforms To [`NSSecureCoding`](/documentation/Foundation/NSSecureCoding) [`Sendable`](/documentation/Swift/Sendable) [`NSCopying`](/documentation/Foundation/NSCopying) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) [`Hashable`](/documentation/Swift/Hashable) [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`Equatable`](/documentation/Swift/Equatable) [`CVarArg`](/documentation/Swift/CVarArg) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`NSCoding`](/documentation/Foundation/NSCoding) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)