UPDATE all entities in the database.
All rows that match the entity key are considered as existing and are
UPDATED in the database.
Updating entities using a custom key from file importation is a typical scenario.
ChangeTracker being outstanding to track what’s modified, it lacks in term of scalability and flexibility.
SaveChanges require one database round-trip for every entity to
update. So if you need to
update 10000 entities, then 10000 database round-trip will be performed which is INSANELY slow.
BulkUpdate in counterpart offer great customization and require the minimum database round-trip as possible.
|Operations||1,000 Entities||2,000 Entities||5,000 Entities|
|SaveChanges||1,000 ms||2,000 ms||5,000 ms|
|BulkUpdate||50 ms||55 ms||65 ms|
How can I specify more than one option?
You can specify more than one option using anonymous block.
How can I specify the Batch Size?
You can specify a custom batch size using the
Read more: BatchSize
How can I specify custom columns to Update?
You can specify custom columns using the
Read more: ColumnInputExpression
How can I specify custom keys to use?
You can specify custom key using the
Read more: ColumnPrimaryKeyExpression
How can I include child entities (Entity Graph)?
You can include child entities using the
IncludeGraph option. Make sure to read about the
IncludeGraph since this option is not as trivial as others.
Read more: IncludeGraph
Why BulkUpdate doesn’t use the ChangeTracker?
To provide the best performance as possible!
Since using the
ChangeTracker can greatly reduce performance, we choose to let
BulkSaveChanges method to handle scenario with
BulkUpdate scenario without it.
Why BulkUpdate is faster than BulkSaveChanges?
The major difference between both methods is
BulkSaveChanges use the
ChangeTracker but not the
By skipping the
ChangeTracker, some methods like
DetectChanges are no longer required which greatly helps to improve the performance.