Composite key in SQL is one to many and not much to a right?

If I create a table with a composite key(One to many relationships). How do I ensure that the one-to-many relationship is one sided? What I mean is A and B are composite keys; A can have multiple B's, But B cannot have Multiple A's Edit: Changed the

Update an entity with a multiple relationship

I have a Suppliers table with the following schema: | SupplierId | SupplierName | ----------------------------- | 1 | Good Company | I also have one-to-many table SupplierActivityHours with the following schema: | Id | SupplierId | Day (enum) | OpenH

Entity Framework modeling the one-to-many relationship

I don't know how to configure following relations in EF: Imagine I need to create some language dictionary model. I have an item (word for example) in one language and in another language. There is some relation between these two items. For instance:

JPA Hibernate one to many

Really confused by how one to many works in JPA, all the documents that I read, uses both one to many and many to one in their example, and I don't know if they are necessary or not, and it doesn't work when I tried it. My question is, suppose I have

Hibernate one to many and many to a relationship

These two questions answered many of my questions, but I am still struggling to think about in real scenario! Taking an example from the references. Assume I have one Order and Multiple Items associated with it. Now assume One Item can have one Retur

Registering associated records in laravel

I have users, and users belong to a dealership. Upon user registration, I'm trying to save a new user, and a new dealership. User database has a dealership_id column, which I want to be populated with the ID of the newly created dealership. This is m

Show one to many relationship data

I'm facing a problem with displaying records using CodeIgniter. I've done this using pure PHP code but I'm quite confused how can I do it using CodeIgniter. Doctor Doctor Specialty Rashid Cardiology, Gastroenterology , Neurology Controller code: publ

Manage a one-to-many relationship using ArrayList

I'm struggling to use one-to-many relationship in my small android project. I have distilled the problem (I'm learning java). My program crashes when tries to add the a child object to a parent. I have spent some time to solve it. I need little suppo

define one-to-many and many-to-many relationships in grails

i have two domain : User and Task such as : 1) a user can be the author of many tasks 2) a user can participate in many tasks,in the same time,a task can have many users which participate in so,i want to define a one-to-many for 1) and a many-to-many

How to map an ArrayList from primitives to a single column?

Let's say I have the following situation: Object Car has an ArrayList of prices, which are all numbers. Is it possible in Hibernate to save all the prices in a single column? I know this violates the first normal form but there might be cases when yo

how to flatten a model with NHibernate

Say I have three tables Products, Languages and ProductTranslations that look like the following: (1) ProductId (1) StandardName (1) Price (2) LanguageId (2) LanguageName and (3) ProductTranslationId (3) ProductId (3) LanguageId (3) LocalName (3) Loc

deleting associated entities in a one-to-many relationship

I have this domain: public class Phone { public int Id { get; set; } public string Number { get; set; } public Person Person { get; set; } } public class Person { public int Id { get; set; } public IList<Phone> Phones { get; set; } } I load a Person

SUBQUERY in NSPredicate and NSInvalidArgumentException

I set up the following model in Core Data. Book has a to-many relationship, called toBookOrders, with OrderBook entity. The inverse is called toBook. Book has a BOOL value property called isSync. I set up the following NSPredicate. NSEntityDescriptio

Update an entity (OneToMany relationship)

i got 2 entities, Student and Phone, and a relationship one-to-many between them. @Entity @Table(name = "STUDENT") public class Student { private long studentId; private String studentName; private Set<Phone> studentPhoneNumbers = new Hash

PHP Sending mass mail: One for everyone or one for all?

When sending mass mails with PHP, is it better to send each subscriber an e-mail (running a for loop through all the e-mail addresses) or is it better to just add all in BCC in a comma separated list and thus sending only one e-mail? Thank you.There'

how to create a one-to-many relevance on google-app-engine

like one forum has many topic , ths specific is : forum and topic has the same model : class Geo(db.Model): #self = db.SelfReferenceProperty() title = db.StringProperty() link = db.StringProperty() updated = db.DateTimeProperty(auto_now =True) author

Android: SQLite one-to-many design

Anyone has good advise on how to implement one-to-many mapping for SQLite using ContentProvider? If you look at Uri ContentProvider#insert(Uri, ContentValues) you can see that it has ContentValues param that contains data to insert. The problem is th

nHibernate one-to-many inserts but does not update

Instead of getting into code, I have a simple question. Default behavior for a simple one-to-many is that it inserts the child record then updates the foreign key column with the parent key. Has anyone ever had a one-to-many where the child object ge

Linq to Sql Many-One relationship

I have 2 views in SQL set up: PurchaseOrder PurchaseOrderLineItems These have many columns aliased (the tables they view/join are not sensibly named... it's a 3rd party product) I have 2 classes (simplified below) class PurchaseOrder { public string

A lot to a join help for the flat file

I'm not sure if this has already been asked – I looked around for quite a bit but couldn't find anything. My end result is to get data from several of my SQL database tables into a comma delimited flat file. Normally this would not be a problem but d