relationships

MySQL Foreign Key On Delete

由 强颜欢笑 提交于 2019-11-27 05:33:39
问题 I am trying to figure out relationships and deletion options. I have two tables, User and UserStaff , with a 1:n relationship from User to UserStaff (a user can have multiple staff members). When my User is deleted, I want to delete all of the UserStaff tables associated with that User . When my UserStaff is deleted, I don't want anything to happen to User . I understand that this is a cascading relationship, but I'm not sure which way. i.e. Do I select the existing foreign key in my

Hibernate: Where do insertable = false, updatable = false belong in composite primary key constellations involving foreign keys?

由 一个人想着一个人 提交于 2019-11-27 00:06:14
When implementing composite primary keys in Hibernate or other ORMs there are up to three places where to put the insertable = false, updatable = false in composite primary key constellations that use identifying relationships (FKs that are part of the PK): Into the composite PK class' @Column annotation (@Embeddable classes only) or Into the entity class' association @JoinColumn/s annotation or Into the entity class' redundant PK property's @Column annotation (@IdClass classes only) The third is the only way to do with @IdClass and JPA 1.0 AFAIK. See http://en.wikibooks.org/wiki/Java

RestKit Object Mapping Relationships without KVC

由 本小妞迷上赌 提交于 2019-11-26 22:59:17
问题 After reading the Object Mapping-Guide on GitHub for RestKit my problem didn't disappear, so perhaps somebody can say if RestKit could deal with the following idea. Entities with Relationships Company - unitID - companyID - name - contacts* (Company -->> Contact | 1:n) Contact - unitID - companyID - contactID - lastName - firstName - account* (Contact >--> Company | 1:1) JSON (Company) [ { "unitID":"003CABD8DEB5DC13C", "companyID":"BSP-002999", "name":"Testcompany" } ] JSON (Contact) [ {

Hibernate: Where do insertable = false, updatable = false belong in composite primary key constellations involving foreign keys?

由 梦想与她 提交于 2019-11-26 12:23:05
问题 When implementing composite primary keys in Hibernate or other ORMs there are up to three places where to put the insertable = false, updatable = false in composite primary key constellations that use identifying relationships (FKs that are part of the PK): Into the composite PK class\' @Column annotation (@Embeddable classes only) or Into the entity class\' association @JoinColumn/s annotation or Into the entity class\' redundant PK property\'s @Column annotation (@IdClass classes only) The

Laravel merge relationships

由 寵の児 提交于 2019-11-26 09:56:27
问题 Is there a way to merge 2 relationships in laravel? this is the way it\'s setup now, but Is there a way I could return both merged? public function CompetitionsHome() { return $this->HasMany( \'Competition\', \'home_team_id\' ); } public function CompetitionsGuest() { return $this->HasMany( \'Competition\', \'guest_team_id\' ); } public function Competitions() { // return both CompetitionsHome & CompetitionsGuest } 回答1: Try out getter method for property which returns merged collections
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