EF Core MySQL Database First?

Question

I have a MySQL database sitting in Amazon Cloud (RDS). It is a tiny database with only one table.

I want to use EF Core, Database First. I know that the Pomelo.EntityFrameworkCore.MySql package is popular, but I cannot see any information on how to achieve a scaffolding of the Db Context via that package.

I followed the instructions here whilst replacing MySql.Data.EntityFrameworkCore.Design with Pomelo.EntityFrameworkCore.MySql but when I ran the command below in Package Manager Console:

Scaffold-DbContext "Server=my-db.rds.amazonaws.com;database=TestDb;uid=blah;pwd=blah;" Pomelo.EntityFrameworkCore.MySql -OutputDir Models -f

I just got the error:

The specified framework version '2.0' could not be parsed

What am I missing? Here's how my dummy solution looks

screenshot of solution

Maybe it is a [bug](https://github.com/dotnet/cli/issues/8735) please update EF Core to min 2.0.2 and try again. As far as I see in your linked article you need to install [MySql.Data.EntityFrameworkCore](https://www.nuget.org/packages/MySql.Data.EntityFrameworkCore/8.0.10-rc) too. An approach would be to follow the [instructions](https://dev.mysql.com/doc/connector-net/en/connector-net-entityframework-core.html) from beginning and after that follow the DB first approach. — ChW, Mar 27 '18 at 09:59
Just note that EF Core really doesn't have a "database first" approach supported. The `Scaffold-DbContext` method mentioned in Zameer's answer will create a DbContext and Models based on an existing database, but you're expected to go "Code First" from there on out as there's no method to update a DbContext with db changes after scaffolding. — Valuator, Mar 27 '18 at 22:04

score 3 · Accepted Answer · answered Apr 13 '18 at 18:48

You need to have these references in your .csproj. Of course, the versions might vary.

<ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.1.0-preview2-final" />
    <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="2.0.1" />
    <PackageReference Include="Pomelo.EntityFrameworkCore.MySql.Design" Version="1.1.2" />
</ItemGroup>

<ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.1.0-preview1-final" />
</ItemGroup>

Note: I had to manually add DotNetCliToolReference to Microsoft.EntityFrameworkCore.Tools.DotNet (not via Manage Nuget Packages view in the Visual Studio)

Gvs Akhil · Answer 2 · 2020-02-19T07:04:39.760

In 2020 with .net core 3 released a lot of things changed, this is what working as of now :)

Make sure you have all these packages

<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.1">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="3.1.1" />
    <PackageReference Include="Pomelo.EntityFrameworkCore.MySql.Design" Version="1.1.2" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.1" />

Now dotnet ef is a global tool that needs to be installed, reference

dotnet tool install --global dotnet-ef

Then run this command, reference

dotnet ef dbcontext scaffold "Server=localhost;Database=ef;User=root;Password=123456;TreatTinyAsBoolean=true;" "Pomelo.EntityFrameworkCore.MySql"

For scaffolding in a different path, you can use --output-dir

dotnet ef dbcontext scaffold server=localhost;port=3306;database=palle2patnam;uid=root;password=password" "Pomelo.EntityFrameworkCore.MySql" --output-dir Models

For forcing to get new fields from database u can add --force

dotnet ef dbcontext scaffold "server=localhost;port=3306;database=palle2patnam;uid=root;password=password" "Pomelo.EntityFrameworkCore.MySql" --output-dir Models --force

score -1 · Answer 3 · answered Mar 27 '18 at 22:00

Install the following NuGet packages by selecting either Package Manager Console or Manage NuGet Packages for Solution from the Tools and then NuGet Package Manager menu:

Microsoft.EntityFrameworkCore.Tools version 2.0.1 (for EF Core 2.0)

Pomelo.EntityFrameworkCore.MySql version 2.0.1

After Installing the above run the below command in Package Manager Console:

Scaffold-DbContext "Your connection string here" Pomelo.EntityFrameworkCore.MySql -OutputDir Models -f

EF Core MySQL Database First?

3 Answers3