I try to save Customer and Contact entities in one form.
My Customer Entity fields:
Id
Name
LastName
ContactId
<- This have relation OneToOne with Id field in Contact Entity.
My Contact Entity fields:
Id
Phone
Address
I try do one form and save this entities to DB.
How to do that?
Thanks for help ;)
If your Entities are well done, you just have to set your Contact to your Customer and save the Customer.
Can you include your annotations (or yml/xml) so we can better understand how you've implemented the OneToOne association?
Related
Hopefully, you can help me with the following doubts that I have.
So I have an entity called User that has some columns like Nationality, Gender, Professional Status. And I have an entity for each column referred.
I'm looking for the best way to define this.
Should I apply a ManyToMany relationship between those tables? Since Users can have the same Nationality and Gender?
When I try to implement this, Spring is creating a third table automatically and I don't understand the need.
Having the following shouldn't be enough?:
Table User:
id,
name,
id_nationality.
id_gender,
id_professional_status
Table Nationality:
id,
nationality
(etc)
Why Spring is creating another table called user_nationality?
Thanks in advance.
Whenever we are using the ManyToMany relationship in that case a separate table will be created containing both primary keys of the tables involved in the new relationship.
I have this table articles and users and I already made model on them and made some relationships with them thru MODEL and some foreign keys. How will I display it in a view like this article is created by this user. How will I query it ? like
$article->user() bla bla.
$query=article::where(['id'=>1])->with('user')->first();
$email=$query->user->email;
print_r($email);
this gives the email of the user with article id 1, if proper models and relationships.
I am using entity framework 6 for one of my project. It has two entities Employee and EmployeeContacts. One employee can have many contacts and I have mapped these relationship in the database. When I return an Employee object it also returns EmployeeContacts that is related to the Employee. I want get only the Employee object excluding contact details
You can use find: var myEmployee = context.Employee.Find(id);
See https://msdn.microsoft.com/en-us/data/jj573936.aspx
What's the best way to handle this scenario?
I have a customer Model(Table) contains contact info for customers
I have Prospect Model(Table) contains contact info for store visitors that aren't customers
I have an Opportunity Model (Table) when either a customer or Prospect visits the store.
In my view I want to generate a new oppportunity. An opportunity can only contain either 1 customer association or 1 prospect association but not both.
In my opportunity model I currently have both the customer and prospect as nullable foreign Id's and and navigation properties. I also have an ICollection<> for Customers and Prospects on the opportunity model.
Is this the right way to do handle a conditional association?
When it comes to the view, I'm stuck on how would I make the customer or prospect association?
I am a computer science student, and this is my understanding on DB relationships:
Since you have two types of "People" - Customer - and Prospect - you could potentially have a table called "Person". In the Person table any common data among both entities would be stored (FirstName, LastName, Address1, Address2, City, State, Zip, etc...).
To indicate that a Person is a Prospect, you would have a Prospect table, which would have a PersonId to link to the person table. You can store more specific attributes about a prospect in this table.
The same would go for a Customer - you would have a Customer table - that would have a PersonId column to link to the Person table, and any specific attributes for the Customer entity.
Now you have a database in which you can derive other entities ... say an Employee entity > you have your base Person Entity to start from. And your Employee table would link back to it, and also have other custom columns for employee specific data.
Does that make sense?
Or maybe I'm going about this all wrong :). Please correct me if I am wrong as I am still a student.
I think you are stuck because you now have two fields on an "Opportunity" record (Customer OR Prospect), one of which MUST be null. With the model I proposed, your Opportunity would link to a Person, in which you can define custom business rules restricting say... an Employee Opportunity (which actually might not be a bad idea).
For the referenced Person in your Opportunity model, it would not be an ICollection (since you specifically said that an opportunity can have ONLY one person). It would simply be a single class such as:
private virtual Person Person { get; set; }
EDIT: If you don't want to restructure your entire database, you could just have a dropdown that asks what type of Opportunity this is (Customer, or Prospect). Based on the selection, you would add a foreign key in your Opportunity table to link to your [Customer or Prospect].
I have two tables, in which one user can have several contacts:
User(UserId, UserName)
Contact(UserId, ContactId)
Suppose I would like to get all the ContactNames from the UserNames in the User Table by the Userid.
Note that the Contact table cannot be seen in the current data context, it has been turned into a many to many relationship
How can I do the query？
What If I need to insert or delete?
I tried the "include" method but it does not work. Do you have any suggestions?
Thank you very much.
var id = 1; // id to find
context.Users
.Where(x=>x.UserId = id)
.SelectMany(x=>x.Users)
.Select(x=>x.UserName)
.ToArray();
After generation from db your model has 2 sub-collections: Users and Users1.
One of it corresponds to users, that are contacts for current user.
Another stores users, that current user is contact for.
You can rename them to represent their meaning to Contacts and ContactsFor via editor.
If you still want to have 2 types instead of Type+(Many-To-Many Ref), then in editor you can delete reference, create new entity Contact, setup all mapping, add references. After all this is done - you will have model look like this:
To Achieve this:
Delete Many-To-Many reference
Crete new Entity Contact
Add properties ContactId and UserId, set StoreGeneratedPattern to none
Add mappings for Contact
Add associations for Contacts and ContactFor
But it's not that easy.