C# – Add “extra data” to LINQ to SQL generated entity

clinq-to-sqlnet

I have a LINQ to SQL entity called Job which is just a simple table in SQL. Most of the time it works for what I need but occasionally I need more fields to be populated in this entity. I know I can use partial classes to add new fields to the LINQ generated class, but my question is how do I populate this extra data? For example, I have a stored proc that pulls back all the values for the Job table and the extra data I need to populate. I'd like to hook into the entity populate routines and when this data is present, populate it, when it's not, ignore it. I know the simple solution is to create a view, but I don't like that solution.

I can't seem to figure out where LINQ is taking the data and populating the entity. Does anyone have any ideas?

Best Answer

(wild guess) you may be able to create an entity from a SQL view. create the view in the db with the joins etc, like in the SP, then add that view to the LINQ designer and it should create an entity with all the gear u need.

(better) Create a class that represents your complete entity (with optional fields) and map to the many entites (you presently have) as another step in the process. This longer coz you will prob want to create another layer of abstraction to do this.. and then to take it further you will prob want to abstract your whole entity set, etc etc.. So its more work.. but it brings you closer to a cleaner Domain Model (if that's what you want).

Related Solutions

.net – Entity Framework vs LINQ to SQL

LINQ to SQL only supports 1 to 1 mapping of database tables, views, sprocs and functions available in Microsoft SQL Server. It's a great API to use for quick data access construction to relatively well designed SQL Server databases. LINQ2SQL was first released with C# 3.0 and .Net Framework 3.5.

LINQ to Entities (ADO.Net Entity Framework) is an ORM (Object Relational Mapper) API which allows for a broad definition of object domain models and their relationships to many different ADO.Net data providers. As such, you can mix and match a number of different database vendors, application servers or protocols to design an aggregated mash-up of objects which are constructed from a variety of tables, sources, services, etc. ADO.Net Framework was released with the .Net Framework 3.5 SP1.

This is a good introductory article on MSDN: Introducing LINQ to Relational Data

C# – the syntax for an inner join in LINQ to SQL

It goes something like:

from t1 in db.Table1
join t2 in db.Table2 on t1.field equals t2.field
select new { t1.field2, t2.field3}

It would be nice to have sensible names and fields for your tables for a better example. :)

Update

I think for your query this might be more appropriate:

var dealercontacts = from contact in DealerContact
                     join dealer in Dealer on contact.DealerId equals dealer.ID
                     select contact;

Since you are looking for the contacts, not the dealers.

Best Answer

Related Solutions

.net – Entity Framework vs LINQ to SQL

C# – the syntax for an inner join in LINQ to SQL

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