Top "Entity-relationship" questions

An entity-relationship model (ERM) is an abstract and conceptual representation of data, information aspects of a business domain or its process requirements.

Delete child objects in Entity Framework

I'm using EF and when I do this: foreach (var reg in detail.Regs) { this.db.Regs.DeleteObject(reg); } I …

entity-framework-4 entity-relationship
Hibernate @OneToMany without a separate join table

Consider the following database schema: create table UserGroup ( id int not null auto_increment, name varchar(200), primary key(id)); create …

java hibernate jpa join entity-relationship
Is there a way to get all managed entities from an EntityManager

I'm setting up a basic test data util and want to keep track of all the data that the EntityManager …

jpa persistence entity-relationship
When to use Associative entities?

Suppose there are two entities called Employee and Campaign. One employee can work on many campaigns. And one campaign can …

entity-relationship
Foreign key mapping inside Embeddable class

I am using eclipselink for JPA. I have an entity, which has a composite key fabricated out of two fields. …

java jpa entity-relationship composite-key embeddable
What is the difference between an entity relationship model and a relational model?

I was only able to find the following two differences: The relationships in an E-R model are explicitly defined, while …

database entity-relationship relational junction-table entity-relationship-model
Loading Nested Entities / Collections with Entity Framework

I am trying to Eagerly load all the related entities or collection of Entity in one call. My Entities Looks …

c# entity-framework-4.1 code-first entity-relationship eager-loading
Core Data Relationship Fault

Tracking a familial relationship in Core Data (1 parent entity + 2 types of children, one of which is recursive), trying to create …

xcode core-data interface-builder entity-relationship
How are super- and subtype relationships in ER diagrams represented as tables?

I am learning how to interpret Entity Relationship Diagrams into SQL DDL statements and I am confused by differences in …

database database-design erd entity-relationship
MySQL: Finding rows that don't take part in a relationship

I have two tables: 'movies' and 'users'. There's an n:m relationship between those, describing what movies a user has …

sql mysql join entity-relationship