In case of many-to-many relation through intermediary table; “Cascade” says whether a record will be created/updated in the child table. Whereas “Inverse” says whether a record will be created/updated in the intermediary table e.g. Assume below scenario 1 student can have multiple phones. So Student class has property for Set of phones. Also 1 Phone …
Combining your advice and a script I found online, I made a procedure that will produce SQL you can run to perform a cascaded delete regardless of ON DELETE CASCADE. It was probably a big waste of time, but I had a good time writing it. An advantage of doing it this way is, you …
In the Doctrine2 documentation “9.6. Transitive persistence / Cascade Operations” there are few examples of how you should configure your entities so that when you persist $article, the $topic would be also persisted. In your case I’d suggest this annotation for Topic entity: /** * @OneToMany(targetEntity=”Article”, mappedBy=”topic”, cascade={“persist”, “remove”}) */ private $articles; The drawback of …
Here’s what you’d include in your components table. CREATE TABLE `components` ( `id` int(10) unsigned NOT NULL auto_increment, `typeId` int(10) unsigned NOT NULL, `moreInfo` VARCHAR(32), — etc PRIMARY KEY (`id`), KEY `type` (`typeId`) CONSTRAINT `myForeignKey` FOREIGN KEY (`typeId`) REFERENCES `types` (`id`) ON DELETE CASCADE ON UPDATE CASCADE ) Just remember that you need to use …
ON DELETE CASCADE is fine, but only when the dependent rows are really a logical extension of the row being deleted. For example, it’s OK for DELETE ORDERS to delete the associated ORDER_LINES because clearly you want to delete this order, which consists of a header and some lines. On the other hand, DELETE CUSTOMER …
This is my conclusion of looking into it: The cascade option does not affect the database column constraints, and I believe is used by TypeORM only in evaluating how to save entity relations to the database. We can define entities like this: @Entity() class Book extends BaseEntity { @ManyToOne(() => Author, (author) => author.books, { …
LBP is faster (a few times faster) but less accurate. (10-20% less than Haar). If you want to detect faces on an embedded system, LBP is the default choice, because it does its calculations in integers. Haar uses floats for processing, which have poorer support on embedded and mobile processors; as a result, the performance …
The way you have it mapped, the User is the managing side of the relationship, therefore it will be responsible for updating the join table. Change the JoinTable mapping from User to Group, and make the groupList property of User so it has the mappedBy attribute. That will change the group to the managing side …
From MySQL Documentation: https://dev.mysql.com/doc/refman/8.0/en/create-table-foreign-keys.html Some database systems have deferred checks, and NO ACTION is a deferred check. In MySQL, foreign key constraints are checked immediately, so NO ACTION is the same as RESTRICT.
A foreign key with a 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. You are saying in a opposite way, this is not that when you delete from child table then records …