I have created models from Entity Framework Core 5 using database first approach. I have made some changes in database now.
Is there any way to update models other than Force approach which will overwrite all models?
I usually find it easier to manually update the affected model classes.
Related
I have a project that has a db first approach initially. However, I have difficulty managing to deployment it to the customers. Because it needs some db updates and I do this manually.
Is there any solution to turn over my DB first approach to the code first approach?
My project is developed in .net core and c# language and also my database firstly Oracle and also Postgre.
Thanks in advance.
You could probably:
create ordinary model classes out of the generated model classes
delete everything else related to the DbFirst approach
Create a code first migration based on the model classes mentioned above
Manually insert a row to the __efmigrationshistory table (in every database you use) with the name of you migration created above --> that way the first generated migration won't run again, as it shouldn't because your db schema is already created
I would like to recreate a 10 years old application with newer Technologies like ASP.NET WebAPI, AngularJS and the EF. Unfortunately, I have to stick to the existing database as the new webclient will run parallel with the existing one.
The difficulties:
- Some tables are cleared and refilled with data from other systems every week
- Many tables are referencing each other on non-primarykey fields.
- A lot of the Update/Write logic has been done with stored procedures so far.
Because of the first two things I am not able to use navigation properties when I just create an .edmx Diagramm from the existing db model. The only Workaround which came to my mind, is to use views (updatable views) for the tables without primary keys and just add the missing primary key field to the view.
Unfortunately, all changes made to the .edmx file have to redone whenever I update it from the model.
Is there any better solution? Does it even make sense to work with EF when using a database like that? I would probably still like to go this way because I could at least improve my EF knowhow.
I'm working on a green-field application that has a corporate mandate that Stored Procedures are used for all database interaction.
I'd like to use Entity Framework and leverage Stored Procedure Mapping to gain the benefits of the ORM.
Since we will be developing the database and .NET application in parallel, I'm looking for information to help the database developer/administrator. Does anyone know of a consolidated guide on how to design tables and stored procedures so they can be best integrated with the Entity Framework?
A couple tips I've collected are:
Update Stored Procedures require exactly 1 parameter per table column
There must be an insert, update, and delete Stored Procedure for every table
I want to know as much about how the database should be designed for easy use with Entity Framework because the database is very difficult to change later in our environment.
I wrote a blog post describing the limitations of using mapping in this way after working on this for several months:
The Pitfalls of Mapping the Entity Framework to Stored Procedures
If you want to use Stored Procedures are used for all database interaction, I just don't see the need to use Entity Framework. One good reason of EF is to save time to write T-SQL, and if you don't take advantage of this, why even use EF?
I need to migrate data from many xmls to a sql server db and and it has to be done in a transactions.
I thought about EF and dbContext as it's a UOW in it's own right.
My question is
Can you do Database First at run time?
What I want to do is Read all tables from db store in class/dataset and map the db.column to equivalent in xml file and commit.
This has to work in such a way that if a table is added or column added it will work without any code changes as it is driven by db.
The problem I face is that with Db generated from model if a new column is required somebody later on "unfamiliar with EF" as to add the column "manual job".
I can do what I want with raw ado.net by reading db schema and mapping to a dataset but wondering if I could do it using EF.
Hope all clear
any suggestions
Yes you can.
You can use Entity Framework Power Tools which allows you to create Code-First file from Database of yours as you start like Code-First.
Or, you can use Database-first approach also. It's not that hard.
If you try to use database-first approach, please read my trial-and-error experience: post1, post2
Is it possible to use Entity Framework 4.3 without linking the model to an actual DB in the back-end?
I need to build a conceptual model of a database in the VS designer and then I'd like to manually handle fetches, inserts and updates to various back-end databases (horrible legacy systems). I need to be able to do this without EF moaning about not having tables mapped, etc. I realise that this is a very odd thing to want to do...
The reason for this is that we would like to move from these legacy systems into a well designed data model and .NET environment, but we need to still maintain functionality and backward compatibility with the old systems during development. We will then reach a stage where we can import the old data (coming from about 6 different databases) into a single DB that matches the EF model I'm building. In theory, we should then be able to switch over from the hacked up EF model to a proper EF model matching the new data structure.
Is this viable? Is it possible to use the EF interface, with LINQ without actually pointing it to a database?
I have managed to query the legacy systems by overriding the generated DbContext and exposing IQueryable properties which query the old systems. My big fight now is with actually updating the data.
If I am able to have EF track changes to entities, but not actually save those changes. I should be able to override the SaveChanges() method on the context to manually insert into various legacy tables.
I'm sort of at wits end with this issue at the moment.
UDPATE 4 Sept 2012: I've opted to use the EDMX file designer to build the data model and I generate the code by using T4. This enables me to then manually write mapping code to suit my needs. It also allows me to later perform a legacy data migration with relative ease.
If I were in your situation I'd setup the new DB server and link the legacy servers to it. Then create stored procedures to interface with EF for the INSERT/UPDATE/DELETE. This way your EF code remains separate from the legacy support messiness. As you decommission the legacy DB servers you can update your stored procedures accordingly. Once you have no more legacy DB servers you can either continue using your sprocs or do a refresh of your EF data connection to use the table schema directly.
Entity framework is to link entities to a data store without manual populates.
Otherwise you're just using classes with linq.
If you mean you don't want a seperate data store like sql server, mongo etc etc, then just let your application create the database as an mdb file that gets bundled in your app_data file. That means you don't need a databsae server so to speak and the database is part of your app.
If on the other hand you want a different way to save to the database, you can create your own data adapters to behave however you like. The mongo .net entity framework component is an example of this.
Alternatively, using code only you can just use stored procedures to persist to the database which can be a bit verbose and annoying with EF, but could bridge the gap for you you and allow you to build a good architecture with a model you want that gets translated into the crappy one in your repositories.
Then when the new database is ready, you can just rework your repo's to use savechanges and you're done.
This will of course only work with the code only approach.