How to add new class to existing edmx file - entity-framework

Assume that I have added a product table into sql server DB. How to generate product class to existing edmx file?

you have to update your edmx file right click on the screen and Click on Update Model From Database. then a window will come select you table from the tables and follow the wizard.
when you finish the wizard then you will find your selected table entity in the edmx and the generated class will b in yourmodel.tt file
then you have to go to the youmodel.context file and make property for the new class like
public DbSet<yourClass> ex { get; set; }
and then you good to go
for ref follow the Link

Whenever you add a new table to you database, you need to update you Edmx. For that simply open you edmx and right click --> select update model form database and select you newly added table and then click finish. Your model will be updated and new classes will be automatically added.

Related

Cannot generate ADO.NET Entity Data Model, model class is empty

So I follow all the steps to create the ADO.NET Entity data model, right click the Model folder, click Add New Item -> ADO.NET Entity Data model -> Generate from Database, and then select the database connection and enter the namespace of my models, and click Finish. However the edmx view looks like this:
I built the solution, still the same. And after the build, the model class is not generated, I can only see:
//------------------------------------------------------------------------------
// <auto-generated>
// This code was generated from a template.
//
// Manual changes to this file may cause unexpected behavior in your application.
// Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
There is no class definition is found here. I checked SQL Server, the table and its data are there. What have I missed?
The table or view does not have a primary key defined and no valid primary key could be inferred. For this reason, this table or view has been excluded. To use the entity, you will need to review your schema, add the correct keys.
If your table has been accidentally removed, add it back to the DBML file and recreate the ADO.NET Entity Data model.

Entity Framework database first adding new table to exist .edmx

I added a new table to the database. In the .edmx (where database diagram is at), I right-clicked and chose 'Update Model from Database...'. I can see the new table's diagram has been generated, but how do I add model to EXISTING .tt? I know I could do it manually, but I would like to know how to generate it automatically. Thanks.
EDIT: I got the model class by clicking around. I think it was right clicking on .tt then 'Debug T4 template' which generated it. But can anybody explain what did this Debug T4 template debug?

Can't select the database when updating EF model

I have an edmx model
I right click on it and select Update model from database
The wizard show up .It normally show me Choose Your Data Connexion, but not anymore. Now it show me directly Choose Your Database Objects
How can I select a different database ?
PS: When I create a second edmx in the same project and want to update it, the second one works like it should
After some trials, I found it.
You must delete the connection string in your config file (app.config in my case)

How to update only one table for model from database with Entity Framework?

I have a model generated from db with Entity Framework. When I have any change in database, I update model from database to get the change in model. But this update is applied to all entities (tables) included in model.
Now I add a new column in a table Tab1. I don't want to update model from database as some other changes that I don't want to include in model. I can add the new property in model for entity Tab1 manually. then it caused mapping error.
So I need to update Model.Store for the table to include the new column. It means I want to update model only for Tab1.
How can I do this?
The EDMX file is an XML file that is a combination of 3 different parts that make up the whole thing. If you right-click on your EDMX file and choose "Open with... XML Editor" you'll see the 3 different sections:
<edmx:ConceptualModels>
<edmx:StorageModels>
<edmx:Mappings>
These sections can be edited manually, at your own risk! :-)
That way you can modify only what you need to.
Note that it's also possible to generate CSDL, SSDL & MSL files rather than having them embedded in the binary file, by changing the "Meta Artifact Processing" property of your model to "Copy to Output Directory".
If you don't want to do this manually, there's the Huagati DBML/EDMX tool, it is free and you can download it from huagati official site or from visual studio gallery, which is a Visual Studio plugin that allows you to select what changes need to be done.
I use following (Conditional) trick. This could be done only when no Table depends on the table which you want to update.
Delete the table which needs to be updated.
Right click on Model and select 'Update Model From Database'. The Table would be shown in the tab 'Add'. Select this table and Update the model.
Precaution : If other existing tables have changes in them, EF would update these changes as well.
There is way of doing it automatically.
right click edmx file > update model from data base > Refresh tab > Tables > select the table(you want to update) and press finish that's it.

LLBLGEN, how to update an existing entity

I have entity Customer under group name Customers
I moved the Customer entity to a new group TestCustomers
The Customer db table changes in the meantime renaming a field from LastName to Surname
I do a Refresh Relational Model Data from a Database in the Catalog Explorer
No changes can be seen in my TestCustomers\Customer entity as it still has a field named LastName
Is this because the Designer has some kind of binding between it and the old entity path Customers\Customer?
How can I achieve the update I want?
In LLBLGen Pro v3.5 you can try this:
In the Entity Editor, click on the Field mappings tab.
Click the Remove mapping button.
Click the Create mapping button.
Choose the correct target from the dropdown list.
This should re-create your entity including any new fields in your target db table.
There is also the Reverse-engineer unmapped target fields which can be used for this, but I found it was disabled for my entities until I remapped them. See documentation here:
http://www.llblgen.com/documentation/3.1/Designer/Functionality%20Reference/TypedViewEditor_FieldMappingsTab.htm