Skip to main content

EFCore - Scaffold-DbContext how to use

EFCore versions, we don't have GUI to manage the DB-entities & dbContext like we used to have with EF6 (or EF5/4 version). With EFCore we've the Scaffold-DbContext command which helps us to create entities & DB context from our DB-objects. 

Let's see how to use Scaffold-DbContext:

Assume we're connecting with SQL Server so after creating a sample project you'll have to install EFCore related libraries as mentioned below. 

Install entity-framework-core for SQL Server, at this time 3.1.9 is the latest stable version 

  •  Microsoft.EntityFrameworkcore 
  •  Microsoft.EntityFrameworkCore.SqlServer 

To use Scaffold-DbContext, following two NuGet packages are required

  • Microsoft.EntityFrameworkCore.Tools 
  • Microsoft.EntityFrameworkCore.Design

Let's say we've two DB tables (e.g. dbo.Employees & dbo.Users ) 



Now let's see how to use Scaffold-DbContext to create c-sharp entities for those two tables:


Open Package manager console

Visual Studio => Tools => NuGet Package Manager => Package Manager Console



Your package manager console will appear like this:



Now run Scaffold-dbContext command like this:

Here in the connection string, either you can use integrate security or user-name/password combination. 
  • To create a separate directory for dbContext use -ContextDir option
  • To create custom dbContext name use -Context option 

the command is something like this. 

Before executing this command make sure you've selected the "Default project" where you want to create the entities & DB context (e.g. TestWebApp.DataAccess)  

Scaffold-DbContext 'Data Source=localhost;Initial Catalog=TestDatabase;Integrated Security=True' 
Microsoft.EntityFrameworkCore.SqlServer 
-OutputDir Models -Tables "Dbo.Employees","Dbo.Users" 
-ContextDir "MyContextDir" -Context MyTestContext


Atest successful execution of this command your "Package manager console" will be like this. 


And in your project, you can observe the related entities for your db-objects & your context 






Labels:

Comments

Post a Comment

Popular posts from this blog

EFCore - Collate function

Search in SQL server query is generally case insensitive (by default or based on database level collation). Suppose we have an employees table with a row having first-name column value as "My-First-Name", so if we want to do the case-sensitive search we have to explicitly use the related collate: In EF 5 (currently in Release Candidate version [RC.2.20475.6]) Collate function got introduced which helps us to use our specific collation based search.  C# with EF5 code sample: var employeeCaseSensitiveSearch = _dbContext.Employees .Where(x => EF.Functions.Collate(x.FirstName, "Latin1_General_CS_AS") == "my-first-name") .FirstOrDefault(); A related database query will be something like this: T-SQL: Case sensitive search (use specific collation e.g.: Latin1_General_CS_AS) SELECT * FROM dbo.Employees AS e WHERE e.FirstName Collate Latin1_General_CS_AS = 'my-first-name' Some of the useful CSharp function which g...
Post a Comment
Read more

Git - Update submodule

Sometimes in the large project when we separate it in different repositories we need to take reference of one repository in another where some the sub-module concepts. Now if we move our submodule to a different repository or renaming its repo-path then we've to also update the repository where this sub-module is getting referenced. Let's see how to update the git submodule.  Step-1: First clone the repo Step-2: Open git UI to create a new local branch from master  Step-3: Open git bash -- Now run below command to (remove submodules & add them):  -- Remove submodule git submodule deinit YOUR_FIRST_REPO git rm YOUR_FIRST_REPO git commit -m "Removed submodule YOUR_FIRST_REPO" rm -rf .git/modules/YOUR_FIRST_REPO -- Add submodule git submodule add <<..YOUR_FIRST_REPO git URL>> Step-4: All good, let's push our changes to the master
Post a Comment
Read more

EFCore - Update command is not updating the underlying data

Why my update command using EFCore is not updating the underlying data in the database though in middle-tier code it's successful, not throwing any error? Let's try to get the root cause and how to solve this.  When creating the model class of related database object if the primary key name is Id then no need to explicitly mention the Key in ef-core OnModelCreating.  But if we've key name different from Id then we have to explicitly mention it in our OnModelCreating. Something like this:  entity.HasKey(c => new {c.CustId }); Assume in the database we've Customers table like this: CREATE TABLE [dbo].[Customers]( [CustId] [INT] IDENTITY(1,1) NOT NULL Primary Key, [FirstName] [VARCHAR](50) NULL ) Point to ponder: In the database table, column CustId is already defined as Primary key.  In EFCore model setup, it's up to us to configure the Key as (custId) or configure it as HasNoKey() Assume we've set our entity with Ha...
Post a Comment
Read more