![]() It can reduce the complexity of writing multiple queries and adds an extra layer of performance optimization.Bulk Extensions Upsert / MergeĮntity Framework Extensions provides the BulkMerge extension method that allows you to perform bulk inserts and updates into the database in a single operation. The BulkMerge method makes that operation very easy to use and improves the performance by 5000% depending more on the provider. The easiest and fastest way to merge data is by using the Entity Framework Extensions third-party library. Data that exists in the database will be updated, and non-existing data will be inserted.Ī BulkMege has also other name such as add or update or insert or update operations. In other words, a merge is equivalent to an UPSERT (Update/Insert) operation. It makes sure that it’s not possible to add multiple users with the same name.BulkMerge is a database operation that combines the insert and update operation into a single, efficient database call. In our case, we’re adding the name attribute to make this property unique. This is a comma-separated list of attribute names. Underneath the class section, you’ll find an option to configure constraints. Let’s change this by adding constraints to our data model:Ĭonfiguring constraints in a Core Data entity. There’s no logic in place to prevent us from having multiple users with the same name. Without constraints in Core Data you could end up with duplicate entries. Without constraints, we could easily end up with the following list after saving: For the sake of this example, we’re consistently adding a user with the same name. This creates a basic view with a list of users and navigation bar buttons to add new users and save the new entries. Let user = User(context: managedObjectContext) Struct ContentView: View var User.entity(), sortDescriptors: ) var users: FetchedResults ![]() To show you exactly how this works we’re going to use a SwiftUI view which is making use of Core Data: Using SwiftUI to visualize constraints in Core Data On top of that, you need to look up for existing values using a fetch request which is less performant! This could easily lead to a lot of extra code to build up a fetch request with a given predicate. Update existing user with given values Without using constraints in our entity configuration we could easily end up with code looking like this: ![]() To learn more about using awakeFromInsert in combination with primitive values I recommend reading my blog post NSManagedObject events: handling state in Core Data. Our goal is to implement a structure in which we ensure this uniqueness. The email is unique to the user and there should, obviously, only exist one. Our entity contains a name, email, and a public identifier. SetPrimitiveValue(UUID().uuidString, forKey: #keyPath(User.publicIdentifier)) To explain to you how constraints in Core Data work we’re going to configure a User entity in a Core Data model:įinal class User: NSManagedObject, Identifiable var name: var email: var publicIdentifier: String! Maintaining a unique set of Core Data entries Automatic code signing and publishing with really good documentation. Fast builds on M1 machines and predictable pricing. Ship your iOS apps faster! CI/CD for iOS and macOS developers.
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