Entity Framework Extensions Delete from Query
DELETE all rows from the database using a LINQ Query without loading entities in the context.
DELETE statement is built using the LINQ expression and directly executed in the database.
// DELETE all customers that are inactive context.Customers.Where(x => !x.IsActive).DeleteFromQuery(); // DELETE customers by id context.Customers.Where(x => x.ID == userId).DeleteFromQuery();
Deleting entities using
SaveChanges normally requires loading them first in the
ChangeTracker. These additional round-trips are often not necessary.
DeleteFromQuery gives you access to directly execute a
DELETE statement in the database and provide a HUGE performance improvement.
|Operations||1,000 Entities||2,000 Entities||5,000 Entities|
|SaveChanges||1,000 ms||2,000 ms||5,000 ms|
|DeleteFromQuery||1 ms||1 ms||1 ms|
Why DeleteFromQuery is faster than SaveChanges, BulkSaveChanges, and BulkDelete?
DeleteFromQuery executes a statement directly in SQL such as
DELETE FROM [TableName] WHERE [Key].
Other operations normally require one or multiple database round-trips which makes the performance slower.
EF Core & Client Evaluation
DeleteFromQuery use the SQL generated by EF Core. When a filter is made on client-side, it means the filtering happens in the application and not in the SQL executed.
In other words, even if you put a filter, all rows tables could be potentially deleted if the filter is made on the client-side.
We always recommend to disable the client evaluation to avoid performance issue in your application.