EF Core Bulk Insert Discover How to Insert Thousands of Entities

Introduction

When you want to insert hundreds, thousands, or millions of entities using SaveChanges() method, you will notice that your application performance is INSANELY slow. Because SaveChanges() requires one database round-trip for every entity to insert. So if you need to insert 10000 entities, then 10000 database round-trips will be performed and your application suffers from performances issues.

Entity Framework Core has made great improvement and is way faster than EF6, but your application performance can even faster than that by using a 3rd party library Entity Framework Extensions.

BulkInsert

Entity Framework Extensions provides an extension method BulkInsert which requires the minimum database round-trips as compared to SaveChanges(). By example under the hood for SQL Server, a simple SqlBulkCopy could be performed.

Performance Comparisons

Steps to use BulkInsert

1. CREATE a list
2. ADD entity to the list
3. USE BulkInsert
4. Done!

using (var ctx = new CustomerContext())
{
    // 1. CREATE a list
    List<Customer> customers = new List<Customer>();
    
    foreach(var line in lines)
    {
        var customer = new Customer();
        // ...code...
        
        // 2. ADD entity to the list
        customers.Add(customer);
    }
    
    // 3. USE BulkInsert
    ctx.BulkInsert(customers);
    
    // 4. Done!
}

Read more: BulkInsert