Bulk Merge (Enterprise Feature)

Description

MERGE all entities from the database.

A merge is an UPSERT operation. All rows that match the entity key are considered as existing and are UPDATED, other rows are considered as new rows and are INSERTED in the database.

This feature is provided by Z.EntityFramework.Extensions that's used by more than 2000 customers all over the world.

// Easy to use
ctx.BulkMerge(list);

// Easy to customize
context.BulkMerge(customers, options => options.ColumnPrimaryKeyExpression = customer => customer.Code);

Try it

Purpose

Merging entities using a custom key from file importation is a typical scenario.

Despite the ChangeTracker being outstanding to track what's modified, it lacks in term of scalability and flexibility.

SaveChanges requires one database round-trip for every entity to insert or update. So if you need to insert or update 10000 entities, then 10000 database round-trips will be performed which is INSANELY slow.

BulkMerge in counterpart offers great customization and requires the minimum database round-trips as possible.

Performance Comparisons

Operations 1,000 Entities 2,000 Entities 5,000 Entities
SaveChanges 1,000 ms 2,000 ms 5,000 ms
BulkMerge 65 ms 80 ms 110 ms