# Core Data and Aggregate Fetches In Swift

DevFeed: [Core Data and Aggregate Fetches In Swift](<https://devfeed.tech/articles/core-data-and-aggregate-fetches-in-swift-37506.md>)

Original publisher: [Read original article](<https://www.cimgf.com/2015/06/25/core-data-and-aggregate-fetches-in-swift/>)

Author: Matt Long

Published: 2015-06-25T16:47:07Z

Content type: tutorial

Language: en

Sources: [Cocoa Is My Girlfriend](<https://devfeed.tech/sources/cocoa-is-my-girlfriend.md>)

Topics: [Swift](<https://devfeed.tech/topics/swift.md>), [iOS](<https://devfeed.tech/topics/ios.md>), [SQLite](<https://devfeed.tech/topics/sqlite.md>), [SQL](<https://devfeed.tech/topics/sql.md>), [Xcode](<https://devfeed.tech/topics/xcode.md>)

Tags: [core-data](<https://devfeed.tech/tags/core-data.md>), [how-to](<https://devfeed.tech/tags/how-to.md>), [ios](<https://devfeed.tech/tags/ios.md>), [sql](<https://devfeed.tech/tags/sql.md>), [sqlite](<https://devfeed.tech/tags/sqlite.md>), [swift](<https://devfeed.tech/tags/swift.md>)

## AI overview

This tutorial explains how Core Data aggregate fetches work in Swift by relating them to SQL-style data grouping and aggregation. It discusses NSExpression and NSExpressionDescription, differences between Core Data and databases, and related batch update and delete capabilities.

## Source excerpt

You can find other articles on the interwebs about NSExpression and NSExpressionDescription, however, I wasn't really satisfied with the explanations I've seen. I decided to write a post myself after I recently had to become much more intimate with the way Core Data aggregate fetches work. I hope this will make clear what has to [...]