When should I delete cascade?
Use the ON DELETE CASCADE option to specify whether you want rows deleted in a child table when corresponding rows are deleted in the parent table. If you do not specify cascading deletes, the default behavior of the database server prevents you from deleting data in a table if other tables reference it.
What is Cascade delete rule?
A foreign key with cascade delete means that if a record in the parent table is deleted, then the corresponding records in the child table will automatically be deleted. This is called a cascade delete in SQL Server.
What is on delete cascade and on delete Set Default?
ON DELETE CASCADE : if a row of the referenced table is deleted, then all matching rows in the referencing table are deleted. ON DELETE SET NULL : if a row of the referenced table is deleted, then all referencing columns in all matching rows of the referencing table to be set to null.
What is restrict delete?
On Delete Restrict: when data is removed from a parent table, and there is a foreign key associated with child table it gives error, you can not delete the record.
Does Entity Framework cascade delete?
Cascade delete automatically deletes dependent records or sets null to ForeignKey columns when the parent record is deleted in the database. Cascade delete is enabled by default in Entity Framework for all types of relationships such as one-to-one, one-to-many and many-to-many.
What is difference between Cascade delete and restrict delete in data integrity?
Cascade Delete – this option means that if you delete a record from one table, corresponding records in the other table are also deleted. Restrict Delete – this option means that if you attempt to delete a record from one table but there is a corresponding record in the other table, the delete operation is not allowed.
What is Cascade and restrict in drop table SQL?
CASCADE has the effect of dropping all SQL objects that are dependent on that object. RESTRICT is the default for the drop behavior. RESTRICT looks to see what objects are dependent on the object being dropped. If there are dependent objects, then the dropping of the object does not occur.