In our company we have a lot of legacy applications which use an edmx file together with EF4.
We would like to migrate to EF6 (or EF core). Is there a way that we can generate the code first objects (dbcontext, entities) from this edmx with the mappings.
How can we do this?
Maybe the best solution for this will be scaffold (reverse engineer your model) from current database.
EF Core has nice powershell tools for this scaffolding https://learn.microsoft.com/en-us/ef/core/get-started/aspnetcore/existing-db
You can also split the whole (maybe big) DbContext to more DbContexts with specified Table parameter
https://learn.microsoft.com/en-us/ef/core/miscellaneous/cli/powershell
EF 6 has also some options for scaffold actual database Entity Framework - Generating Classes
Why would you bother generating anything from .edmx? What if you created new project with code first from existing database?
Related
I'm trying to generate an entity from my SQL database using the ADO.NET Entity Data Model using the ADO.NET DbContext Generator. When I generate my edmx from the database I can see it in the model. I right click on my tt file (which is in a separate project) and run the custom tool. The entity appears. It's called CustomerContact. However, my dbcontext does not have a CustomerContacts collection. What is going on here?
I figured it out. The problem was the different versions of Entity Framework. I updated both projects to the latest version of EF and it works now
In MVC 5 ,In my project I have a fileuploading class file with ado.net connection strings and I have other files and data designed in EF. how do I change the code in order to switch from ado.net to EF?
this is a so generally question, but, you need to remove the ado objects, and implement this functionality in EF, using the EF Context, ensure that the dbcontext has the dbset that you need, etc...
Also, if you have more specific questions is better!
What are the benefits of using ADO.Net Entity Model and EF?
Can we use both of them together in a project. I came across an example where, the user had used both edmx and ef for his application. I am not sure what is the purpose of that.
Thanks
Edmx artifact (either in the form of a file on the disk for Model First and Database First approaches or being generated by the EF runtime - Code First approach) describes your model, your database and the mapping between these. At the moment EF always needs it to work. The only nuance is that for CodeFirst applications (or, in general, applications using DbContext) this file is generated on the fly from your classes and you don't deal with it directly while in case of Model First/Database First where you use the ObjectContext the file is on your disk and (usually) is split and embedded in your assembly.
EDIT
EF6 no longer creates and uses artifacts internally (at least for CSDL and SSDL parts). However you can still dump the model in form of EDMX using EdmxWriter.WriteEdmx
I'm following the EF Code-First approach in a project that works against an existing database, to which I'm adding tables as needed.
This database has a number of tables for which I need to generate POCO classes for, and so I was wondering if there was a straight-forward, clean approach, to generating simple POCO classes from the database ... from which I can continue to work with using the general Code-First paradigm?
You can use the Entity Framework Power Tools for that.
If you want just the simple Poco classes without any relations use this T4 template
Generate entity class from database table
We are about to start using EF as our ORM. We have our own MetaData representing the databse stracture and we will generate whatever we need off of that.
We are wondering whether to use the "old" EDMX approace, or to use the new EDMX free approach (wiht DbSet and DbContext). As we do our own code/edmx generation it seems odd to generate an EDMX and then generate objects and context off of it.
The thing is I don't see much talk about about the EDMX free approach. Is it being used by anyone? Can someone with experience share their impressions? Are there known limitations? Are there pros and cons?
Asher
Are you asking if anybody is using code-first? :) By checking the number of questions in entity-framework-4.1 and code-first and ef-code-first I guess people are using it a lot. There were several questions about code-first x non code-first. Some of I answered:
EF POCO code only VS EF POCO with Entity Data Model
EF Model First or Code First Approach?
EF 4.1 Code-first vs Model/Database-first
Generally there are four approaches:
Model first (database generated from EDMX)
Database first (EDMX generated from database)
Code first (database generated from code mapping)
Database first with code mapping (code mapping manually created for existing database or manually updated mapping generated by EF Power Tools CTP)
Selection of the approach usually depends on the way how you want to develop application (as described in linked answers). It also depends if you want to use ObjectContext API or DbContext API. The former one is usually used with first two approaches (but the secret is it should work with code-first as well) the later one with all of them.
Code first has some limitations - it doesn't support all mapping features EDMX does for example:
Stored procedures mapping (it doesn't mean you cannot execute SP when using code first)
SQL functions mapping
Advanced EDMX features like defining queries, query views, model defined functions
etc.
What I don't understand is why are you trying to combine your code generation tool with EF. Either use your stuff or use EF's stuff. You will avoid complications and incompatibilities.