Bulk SynchronizeDirectly execute add, update, and delete operations to mirror data in EF Core

The BulkSynchronize method allows you to mirror data from your source to the database in EF Core. What exactly is a mirror operation?

  • Rows that match the entity key are UPDATED.
  • Rows that exist in the source but not in the database are INSERTED.
  • Rows that exist in the database but not in the source are DELETED.

In other words, your destination table data becomes exactly like the list of entities you provide. The method is similar to BulkMerge, but it also includes the delete step, making it a complete mirror.

It’s also possible to synchronize only a subset of your table with the ColumnSynchronizeDeleteKeySubsetExpression option, or to soft-delete rows with the SynchronizeSoftDeleteFormula option (which we will cover later).

// Easy to use
context.BulkSynchronize(customers);

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

Online Example (EF Core) | Online Example (EF6)

Scenarios

The BulkSynchronize method is fast but also flexible to let you handle various scenarios in Entity Framework such as:

What is supported?

  • All Entity Framework Core Version: EF Core 9, EF Core 8, EF Core 7, EF Core 6, EF Core 5, EF Core 3
  • All Entity Framework Version: EF6, EF5, EF4
  • All Inheritances (TPC, TPH, TPT)
  • Complex Type/Owned Entity Type
  • Enum
  • Value Converter (EF Core)
  • And more!

Advantages

  • Easy to use
  • Flexible
  • Increase performance
  • Increase application responsiveness
  • Reduce database load
  • Reduce database round-trips

Getting Started

Bulk Synchronize

The BulkSynchronize and BulkSynchronizeAsync methods extend your DbContext to let you synchronize a large number of entities in your database.

context.BulkSynchronize(customers);

context.BulkSynchronizeAsync(customers, cancellationToken);

Try it in EF Core | Try it in EF6

Bulk Synchronize with options

The options parameter let you use a lambda expression to customize the way entities are synchronized.

context.BulkSynchronize(customers, options => options.BatchSize = 100);

context.BulkSynchronize(customers, options => {
    options.ColumnPrimaryKeyExpression = customer => customer.Code;
});

Try it in EF Core | Try it in EF6

Real Life Scenarios

Synchronize and keep identity value

Your entity has an identity property, but you want to force to insert a specific value instead. The SynchronizeKeepIdentity option allows you to keep the identity value of your entity.

context.BulkSynchronize(customers, options => options.SynchronizeKeepIdentity = true);

Try it in EF Core | Try it in EF6

Synchronize and include/exclude properties

You want to synchronize your entities but only for specific properties.

  • ColumnInputExpression: This option lets you choose which properties to map.
  • IgnoreOnSynchronizeInsertExpression: This option lets you ignore when inserting properties that are auto-mapped.
  • IgnoreOnSynchronizeUpdateExpression: This option lets you ignore when updating properties that are auto-mapped.
context.BulkSynchronize(customizeToSynchronize, options => {
    options.IgnoreOnSynchronizeInsertExpression = c => c.UpdatedDate;
    options.IgnoreOnSynchronizeUpdateExpression = c => c.CreatedDate;
});

Try it in EF Core | Try it in EF6

Synchronize a subset of the table

You want to synchronize your table, but only a subset of the table and not the whole table, such as only a specific user, type, or category that exists in the entities list provided.

context.BulkSynchronize(customers, options => {
    options.ColumnPrimaryKeyExpression = customer => customer.Name;
    options.ColumnSynchronizeDeleteKeySubsetExpression = customer => customer.Type;
});

Try it in EF Core | Try it in EF6

Learn more here: https://entityframework-extensions.net/column-synchronize-delete-key-subset-expression

Synchronize with custom key

You want to synchronize entities, but you don't have the primary key. The ColumnPrimaryKeyExpression let you use as a key any property or combination of properties.

context.BulkSynchronize(customers, options => options.ColumnPrimaryKeyExpression = c => c.Code);

Try it in EF Core | Try it in EF6

Synchronize with future action

You want to synchronize entities, but you want to defer the execution.

By default, BulkSynchronize is an immediate operation. That means, it's executed as soon as you call the method.

FutureAction: This option lets you defer the execution of a Bulk Synchronize. ExecuteFutureAction: This option trigger and execute all pending FutureAction.

context.FutureAction(x => x.BulkSynchronize(customers));
context.FutureAction(x => x.BulkSynchronize(invoices));

// ...code...

context.ExecuteFutureAction();

Try it in EF Core | Try it in EF6

More scenarios

Hundreds of scenarios have been solved and are now supported.

The best way to ask for a special request or to find out if a solution for your scenario already exists is by contacting us: info@zzzprojects.com

Documentation

BulkSynchronize

Methods
Name Description Example
BulkSynchronize<T>(items) Bulk synchronize entities in your database. EFCore / EF6
BulkSynchronize<T>(items, options) Bulk synchronize entities in your database. EFCore / EF6
BulkSynchronizeAsync<T>(items) Bulk synchronize entities asynchronously in your database. EFCore / EF6
BulkSynchronizeAsync<T>(items, cancellationToken) Bulk synchronize entities asynchronously in your database. EFCore / EF6
BulkSynchronizeAsync<T>(items, options, cancellationToken) Bulk synchronize entities asynchronously in your database. EFCore / EF6
Options

More options can be found here:

Last updated: 2025-03-17
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