Running EF Core migrations does not find environment variable in VS Code

Question

Started building up an API solution with Azure Functions with runtime version 3.x and .NET Core 3.1. In the solution using also Entity Framework Core 3.1 with code first approach.

Check the .csproj file:

<PropertyGroup>
   <TargetFramework>netcoreapp3.1</TargetFramework>
   <AzureFunctionsVersion>v3</AzureFunctionsVersion>
   <RootNamespace>project_name</RootNamespace>
   <PublishWithAspNetCoreTargetManifest>false</PublishWithAspNetCoreTargetManifest> 
</PropertyGroup>
<ItemGroup>
   <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.0.0" />
   <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.3" />
   <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.3">
     <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     <PrivateAssets>all</PrivateAssets>
   </PackageReference>
   <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.0.3" />
</ItemGroup>

In the StartUp class I have the following to create the database context:

public RequestContext CreateDbContext(string[] args)
{
   string sqlConnectionString = Environment.GetEnvironmentVariable("SqlConnectionString");
   var optionsBuilder = new DbContextOptionsBuilder<RequestContext>();
   optionsBuilder.UseSqlServer(sqlConnectionString);
   return new RequestContext(optionsBuilder.Options);
}

So in the project I have my models for migrations and running the command with .NET Core CLI as the following:

dotnet-ef migrations add InitDb

Meanwhile running the Azure Function locally there are no issues, it can read the connection string value from local.settings.json file without any issues. Once running the migrations command I get the following error:

Value cannot be null. (Parameter 'connectionString')

Question:

So it's clear it cannot find the environment variable called SqlConnectionString once running the migrations command. Using Visual Studio 2019 with Package Manager Console there is a way to solve this issue by setting up the environment variable as the following command before running migrations:

$env:SqlConnectionString="Server=<connection-string-value>"

It's pretty annoying to switch between PMC and VS Code just because of this step if I want to run migrations. I was checking different answers in similar topics but none of them helped me that much.

So is there any way to do the same and setup environment variable with VS Code terminal using bash? Or what could be the possible solution for this scenario?

Thank you!

please refer to https://askubuntu.com/questions/26318/environment-variable-vs-shell-variable-whats-the-difference — Jim Xu, May 11 '20 at 07:34
@JimXu Thank you, that was helping me understanding what was leading to my issue. — norbitrial, May 11 '20 at 09:26

norbitrial · Accepted Answer · 2020-05-11T09:34:32.447

The problem was I originally tried to create an environment variable without the export keyword. So with the following command in bash dotnet migrations was leading the Value cannot be null error:

SqlConnectionString="Server=<connection-string-value>"

Based on Jim Xu's comment I created an environment variable which seems to solve the issue as:

export SqlConnectionString="Server=<connection-string-value>"

See the full log:

$ export SqlConnectionString="Server=<connection-string-value>"

$ echo $SqlConnectionString
Server=<connection-string-value>

$ dotnet-ef migrations add InitDb
Build started...
Build succeeded.

Done. To undo this action, use 'ef migrations remove'

The references which were helping the solution were:

Environment variable vs Shell variable, what's the difference?.
Also you can find further information in the SO link: Defining a variable with or without export

Thanks for sharing that link!

Running EF Core migrations does not find environment variable in VS Code

1 Answers1