hi, I am trying to run Add-Migration command in PM. But I am getting an error add-migration : The term 'add-migration' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again. At line:1 char:1 I have all the EF packages installed. Cleared PM settings and restarted. restarted VS. Closed and reopened. All the solutions given on other sites are already tried out. But I am still getting this error.

Hi @ Santhi Dhanuskodi Try to re-install the Microsoft.EntityFrameworkCore.Tools package and clear the NuGet Cache: uninstall Microsoft.EntityFrameworkCore.Tools package, then go to VS Tools -> Nuget Package Manger -> Package Manager Settings -> General Tab ->Clear All NuGet Cache(s) -> install the Microsoft.EntityFrameworkCore.Tools package ->Restart Visual Studio. If still not working, you can try to use the following commands to execute the migration: dotnet ef migrations add addPerson --context ApplicationDbContext --project Test dotnet ef database update --context ApplicationDbContext --project Test The result as below: and If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread. Best regards, Dillion

Verify EF Core tools are installed. https://learn.microsoft.com/en-us/ef/core/cli/dotnet dotnet ef Install the tools globally. dotnet tool install --global dotnet-ef Also, make sure the correct default project is selected in the Program Manager Console.

hi I have verified package is installed. It is there and still I get the error. Below is the screenshot. Also installed EF as per ur suggestion, globally also.

EF - Add Migration Error

Accepted answer

Zhi Lv - MSFT 32,106 Reputation points Microsoft Vendor

2023-07-28T06:16:45.1466667+00:00
Hi @Santhi Dhanuskodi

Try to re-install the Microsoft.EntityFrameworkCore.Tools package and clear the NuGet Cache:

uninstall Microsoft.EntityFrameworkCore.Tools package, then go to VS Tools -> Nuget Package Manger -> Package Manager Settings -> General Tab ->Clear All NuGet Cache(s) -> install the Microsoft.EntityFrameworkCore.Tools package ->Restart Visual Studio.

If still not working, you can try to use the following commands to execute the migration:

dotnet ef migrations add addPerson --context ApplicationDbContext --project Test dotnet ef database update --context ApplicationDbContext --project Test

The result as below:

and

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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Best regards,

Dillion
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Santhi Dhanuskodi 225 Reputation points

2023-07-28T08:12:58.2033333+00:00

Thanks a lot! This works!

I also want to understand what is 'add-migration' and 'update database' will do.

I am assuming it creates a class with up and down method with all column and data fetched from db. If I have 10 records in a table, All these 10 records details will be pulled in to the newly created class file. Is this correct?

Similarly update-database is going to pull data from the class file and updates the table. For eg, if my class file contains 15 reccords, all those 15 records will be inserted into db. Am I right?

Please educate me!

Zhi Lv - MSFT 32,106 Reputation points Microsoft Vendor

2023-07-28T09:54:58.3533333+00:00

Hi @Santhi Dhanuskodi

I also want to understand what is 'add-migration' and 'update database' will do. I am assuming it creates a class with up and down method with all column and data fetched from db. If I have 10 records in a table, All these 10 records details will be pulled in to the newly created class file. Is this correct?

When using add-migration command, it will generate a migration class which contains the Up and Down method as below, as we can see it will according to the model to create table, this command is similar with dotnet ef migrations add addPerson --context ApplicationDbContext --project Test.

public partial class InitialCreate : Migration { protected override void Up(MigrationBuilder migrationBuilder) { migrationBuilder.CreateTable( name: "Course", columns: table => new { CourseID = table.Column<int>(nullable: false), Credits = table.Column<int>(nullable: false), Title = table.Column<string>(nullable: true) }, constraints: table => { table.PrimaryKey("PK_Course", x => x.CourseID); }); // Additional code not shown } protected override void Down(MigrationBuilder migrationBuilder) { migrationBuilder.DropTable( name: "Enrollment"); // Additional code not shown } }

About the seed data, you can use the OnModelCreating method, like this:

protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<Author>().HasData( new Author { AuthorId = 1, FirstName = "William", LastName = "Shakespeare" } ); modelBuilder.Entity<Book>().HasData( new Book { BookId = 1, AuthorId = 1, Title = "Hamlet" }, new Book { BookId = 2, AuthorId = 1, Title = "King Lear" }, new Book { BookId = 3, AuthorId = 1, Title = "Othello" } ); }

More detail information, see EF Core Seed Data . Or refer to this tutorial to create a SeedData method.

Similarly update-database is going to pull data from the class file and updates the table. For eg, if my class file contains 15 reccords, all those 15 records will be inserted into db. Am I right?

When execute the update-database command (this command is similar with dotnet ef database update --context ApplicationDbContext --project Test), it will according to the migration file to create the data table in the database and insert data into database. More detail information, see apply migrations to the Contoso University sample.

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Best regards,

Dillion
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EF - Add Migration Error

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