cascading-deletes - w3toppers.com

What is the difference between CascadeType.REMOVE and orphanRemoval in JPA?

From here:- Cascading Remove Marking a reference field with CascadeType.REMOVE (or CascadeType.ALL, which includes REMOVE) indicates that remove operations should be cascaded automatically to entity objects that are referenced by that field (multiple entity objects can be referenced by a collection field): @Entity class Employee { : @OneToOne(cascade=CascadeType.REMOVE) private Address address; : } Orphan Removal … Read more

How does JPA orphanRemoval=true differ from the ON DELETE CASCADE DML clause

orphanRemoval has nothing to do with ON DELETE CASCADE. orphanRemoval is an entirely ORM-specific thing. It marks “child” entity to be removed when it’s no longer referenced from the “parent” entity, e.g. when you remove the child entity from the corresponding collection of the parent entity. ON DELETE CASCADE is a database-specific thing, it deletes … Read more

On delete cascade with doctrine2

There are two kinds of cascades in Doctrine: 1) ORM level – uses cascade={“remove”} in the association – this is a calculation that is done in the UnitOfWork and does not affect the database structure. When you remove an object, the UnitOfWork will iterate over all objects in the association and remove them. 2) Database … Read more

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

You will have to use the fluent API to do this. Try adding the following to your DbContext: protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<User>() .HasOptional(a => a.UserDetail) .WithOptionalDependent() .WillCascadeOnDelete(true); }

How do I use cascade delete with SQL Server?

You will need to, Drop the existing foreign key constraint, Add a new one with the ON DELETE CASCADE setting enabled. Something like: ALTER TABLE dbo.T2 DROP CONSTRAINT FK_T1_T2 — or whatever it’s called ALTER TABLE dbo.T2 ADD CONSTRAINT FK_T1_T2_Cascade FOREIGN KEY (EmployeeID) REFERENCES dbo.T1(EmployeeID) ON DELETE CASCADE