I'm learning EF DB first, I have updated one table column and I found a solution from the official document to refresh the model.
Right-click anywhere on the design surface, and select Update Model
from Database.
Is there a way to do this programmatically.
Is there any programmatic solution to that?
No. There is no (common) scenario where updating the model from the database is useful without making manual changes to your code. So there would be little point in in automating that.
Related
I am developing an Asp.Net WebForms website. I am used from my prior project to the "dataset designer", it was my main worksite, I had there all my tables and also hundreds of queries which I could easily call from code like this: "this.InventoryTableAdapter.MyQuery('parameters'), it was great, but I can't find such a thing in Asp.Net, am I missing something. how do you access your special queries in code. do you have to write cumbersome ADO.Net code for each small thing, can someone enlighten me please.
You can still add a database designer to your .NET application. Today's standard ORM for .NET is Entity Framework, although many other good options exist. One thing to research is Entity Framework Database First. Here's how to get started...
In your project, choose to Add New Item. In the Add New Item dialog choose the Data items and then select ADO.NET Entity Data Model. Click Add.
In the Entity Data Model Wizard, select EF Designer from database.
If you have database connections defined within your development environment, you may see one of these connections pre-selected. Or, you can create a new connection to your database.
After setting up your connection, select the tables you want to generate models for. These will be the tables available in your database designer.
This is a very high level how to. You can read more about this approach here: https://learn.microsoft.com/en-us/aspnet/mvc/overview/getting-started/database-first-development/creating-the-web-application
Another ORM option is LinqToSql. You can read more about creating a database designer ".dbml" file using LinqToSql here: https://msdn.microsoft.com/en-us/library/bb384428.aspx
I hope this helps.
I am new to Entity Framework. I have created an EF Model and successfully added some tables and relation. Then I Clicked Generate Database from Model and My DB has been updated. Then I renamed some columns and I don't know how to revert or apply the changes. And Update Model from database does not seems to work because the columns names are different yet.
I need to graphically sync DB with Model. I prefer the model data rather than db data.
Thanks in advance.
You might want to look into the Code-First approach of Entity Framework. Using that approach you'll define your model in your code, and when changing anything you can create a Migration which allows you to up- and down-grade the DB to a specific version from the package manager console (or just create the respective SQL scripts).
For more information on this subject please see this article on MSDN
Note that you can also reverse engineer the code first model from an existing database (see 3. Reverse Engineer Model in this MSDN article), and then enable migrations for that model (see Step 2: Enable Migrations in this MSDN article)
What I do when I make "updates" is do it on both sides manually, in db and then in model (by right click properties) if the change is small. If adding a "new" table I drag it over to model from db server connections panel.
The alternative I've seen others prefer to use in this cases is to stay away from Entity Framework and use Dapper where you pass queries to it and it handles the rest.
Dapper (Wins!) vs Entity Framework vs ADO.NET Performance Benchmarking
Let's say you have a database that is currently in use. It has one table that contains some information about Customers.
And let's say that you want to create an application around it. You need to use the Customers table in your program, but you also need to add some new tables, possibly connected to the Customers. For example, you need to add an Orders table that has some association to the Customers table.
I have started to learn Entity Framework. I have learned a bit about "Database-First" and "Model-First" data models. But the situation is, what I want to do doesn't fit into any of these categories. I neither have a completely empty database, nor a finished database schema that can directly be used in the program.
What should I do? If I go with "Model-First" and design my entities using the Visual Studio Designer, can I just use it to create the relevant part of the database schema?
Go with Data-first, THEN go with Model-first. You don't have to pick... use the data-first wizard to generate EF for your existing table, then use the designers to create additional objects, then sync that back to your database. The concepts of model-first and data-first only applies to the initial creating of your EF stuff - anything you do after that can by synced in either direction.
This shows how to put database changes back into your model after it's created - you can do the other way too, but I can't find that article - all the new videos and crap are hard to navigate - you may be able to find it.
http://msdn.microsoft.com/en-us/data/jj206878
After all, the framework wouldn't be very useful if it locked you into never being able to update anything. Right?
The more development into your project, the more Database-First it'll become, so I suggest you to go with Database-First right now and then extent your EF entities and then implement/fake/mock the missing pieces
If you haven't read about TDD, it's time to do so now. It'll save a ton of time down the road especially when working with an ever changing data model.
We are upgrading an old VB6 application which sits on a SQL Server 2005 database, to an Entity Framework solution. The database remains the same, except - we're adding a new table. Is it possible with Entity Framework, to maintain the existing structure, when it gets installed on a client PC - and just add one new table?
Is this how Code First will work? Can I be 100% certain that no other tables will be modified?
i don't think, the effort is worth it to switch to code-first if you have an existing database and want to add only one table.
it is possible to map code-first classes to an existing database (reverse engineer code first). actually, i'm not very experienced with that workflow, but i know you can. You have to deal with a lot of manual mapping (with DataAnnotations or Fluent API), so in your case i would recommend to use the Entity Framework Database First workflow, since adding a single table saves you a lot of work.
this link has some useful information: Arthur Vickers Blog - Don't use Code first by mistake
You have two options, use a database editor such as SQL management studio to create the table which you can then map to a ef entity, or use migrations for ef which will let you update your database via ef.
Take a look at the migrations tutorial here: http://msdn.microsoft.com/en-gb/data/jj591621
I am using the database first approach, since a database developing team is doing the changes I require in the database on the SQL server for me.
Hence, I have to update the EDMX whenever the schema in the database changes.
Note: Changing one single table directly does not work for me, because VS doesn't always detect the changes right (for this issue, here are some details in SO if you're interested).
Hence, I am using the following workaround (regenerating all the tables):
In VS 2012, open the EDMX file by double-clicking on it. The graphic representation of the tables is shown.
Left-Click into the EDMX designer, then select all tables by pressing CTRL+A. Then, remove them by pressing DEL.
Right-Click into the EDMX designer and select "Update Model from Database ..." in the context menu.
The Update Wizard opens. In the "Add" tab, check "Tables", and depending on the requirements, check "Pluralize or singularize generated object names", "Include foreign key columns in the model" and optionally "Import selected stored procedures and functions into the entity model". Usually, I am using the "Pluralize..." and "Include foreign key columns..." options.
Click Finish. Now Save by pressing Ctrl+S.
That workaround works fine for me, and requires just a minute to update the model reliably.
Im using dbml (c# vs2010) to model my database and DataContext.CreateDatabase() to create it. Some time later I add a new property to one entity-type and now I want to upgrade the SQL-database to fit the new version of the dbml-schema. How do I accomplish this? Do I have to delete and re-create the database or upgrade it manually? Is ADO.NET EF better in this respect?
Update:
When searching for methods of updating the database according to changes in dbml I only get results for the inverse; updating dbml from changes in the database. But what is then the visual designer in dbml for? I want some master-design-view where I can do my changes and then generate sql-upgrade-script from that. Isnt that what everyone wants?
Neither Linq2Sql nor EF are made for this kind of scenario.
You asked if this is possible so in response to that I'll say that in theory I guess you could hack around this in EF by altering the schema of your db and using some script to alter the DBML file but I would highly recommend against it. Use the right tool for the job.
Sounds like ADO.NET might be a better solution for you.