one-to-many

来源： https://stackoverflow.com/questions/13940696/hibernate-two-onetomany-properties-mapped-by-the-same-entity-with-different-co

来源： https://stackoverflow.com/questions/63110054/when-creating-credit-cards-for-a-single-user-it-only-updates-the-previous-card

问题 I have couple of failure cases for Unidirectional JPA2 @OnetoMany relationship below is the code snippet @Entity @Table(name="CUSTOMER") @Access(AccessType.FIELD) public class Customer { @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY) @JoinColumn(name="CUSTOMER_ID", referencedColumnName="CUSTOMER_ID") private List<Address> customerAddresses; .... } In this case it fails to create Entity manager factory during server startup with the following error DEBUG - Second pass for collection

问题 I have couple of failure cases for Unidirectional JPA2 @OnetoMany relationship below is the code snippet @Entity @Table(name="CUSTOMER") @Access(AccessType.FIELD) public class Customer { @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY) @JoinColumn(name="CUSTOMER_ID", referencedColumnName="CUSTOMER_ID") private List<Address> customerAddresses; .... } In this case it fails to create Entity manager factory during server startup with the following error DEBUG - Second pass for collection

问题 I'm trying to figure out what I can possibly be doing wrong (or, of course, misunderstood about relationships, fetches and all). In a first search, when I read the question's title, I hoped this question could help me, but I was wrong: SwiftUI TabView with List not refreshing after objected deleted from / added to Core Data Anyway... In my app, when I touch a customer item, the detail view is shown properly with its data. If I change any attribute and go back to the first view, its updated

问题 I'm trying to learn Go and Gorm by building a little prototype order management app. The database is MySQL. With simple queries Gorm has been stellar. However, when trying to obtain a result set involving a combination one-to-many with a has-one relationship Gorm seems to fall short. No doubt, it is my lack of understanding that is actually falling short. I can't seem to find any online examples of what I am trying to accomplish. Any help would be greatly appreciated. Go Structs // Order type

问题 I have a Parent with a OneToMany associations with a Child Table. I'm trying to write a query with CriteriaBuilder to restrict the results returned from the Child table. I'm adding a Predicate, something like cb.equal(parent.get("children").get("sex"), "MALE") If the Parent has a son or SON and Daughter it's returning that parent but also returning all the children they have. Hibernate fires off the first query with my predicates but the second query to get the children only uses the

问题 I have a Parent with a OneToMany associations with a Child Table. I'm trying to write a query with CriteriaBuilder to restrict the results returned from the Child table. I'm adding a Predicate, something like cb.equal(parent.get("children").get("sex"), "MALE") If the Parent has a son or SON and Daughter it's returning that parent but also returning all the children they have. Hibernate fires off the first query with my predicates but the second query to get the children only uses the

问题 I have three tables Employee, Boss, and Address. Employee and Boss in this case share the same Address. When I call EntityManager.remove on Employee I get an Integrity Constraint exception because it tries to delete the Address which it can't because Boss still needs it. If no one is using the Address though I would want it to be removed. What should my annotations look like so that I can delete orphans from Address but avoid the integrity constraint? Exception = Internal Exception: java.sql

问题 I have a tagging system for my events system I would like to create a 'tag cloud'. I have Events, which can have multiple 'categories'. Here's the table structure: **Event_Categories** (Stores Tags / Categories) | id | name | +-----------------+ + 1 | sport | + 2 | charity | + 3 | other_tag | **Events_Categories** (Linking Table) | event_id | event_category_id | +-------------------------------+ + 1 | 1 | + 2 | 2 | + 3 | 1 | + 3 | 2 | Summary: Event ID 1 -> Sport Event ID 2 -> Charity Event