EF Core Database Initialization String Error in Multi-Tier Architecture

[Rahulx1710]

Describe the bug

When attempting to update the database using Entity Framework Core, the following exception occurs:

Format of the initialization string does not conform to specification starting at index 0.

To reproduce

1. I have created a 3-tier architecture:
   Tier 1: Razor Pages project
   Tier 2: Domain and ApplicationDbContext
   Tier 3: Repository layer

2.Below is the code from the Razor Pages Program.cs file:

using DigitalSociety.Data;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();


builder.Services.AddDbContext<ApplicationDbContext>(options =>
{
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapRazorPages();

app.Run();

3. Below is the project reference for the Razor Pages UI project:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.11">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.11" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\DigitalSociety.Data\DigitalSociety.Data.csproj" />
  </ItemGroup>

</Project>

4. Below is the project reference for the Domain side:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.11" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="8.0.11">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

</Project>

Stack Trace

System.ArgumentException: Format of the initialization string does not conform to specification starting at index 0.
   at Microsoft.Data.Common.DbConnectionOptions.GetKeyValuePair(String connectionString, Int32 currentPosition, StringBuilder buffer, Boolean useOdbcRules, String& keyname, String& keyvalue) in /_/src/Microsoft.Data.SqlClient/src/Microsoft/Data/Common/DbConnectionOptions.Common.cs:line 475
   at Microsoft.Data.Common.DbConnectionOptions.ParseInternal(Dictionary`2 parsetable, String connectionString, Boolean buildChain, Dictionary`2 synonyms, Boolean firstKey) in /_/src/Microsoft.Data.SqlClient/src/Microsoft/Data/Common/DbConnectionOptions.Common.cs:line 675
   at Microsoft.Data.Common.DbConnectionOptions..ctor(String connectionString, Dictionary`2 synonyms) in /_/src/Microsoft.Data.SqlClient/src/Microsoft/Data/Common/DbConnectionOptions.Common.cs:line 121
   at Microsoft.Data.SqlClient.SqlConnectionString..ctor(String connectionString) in /_/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlConnectionString.cs:line 297
   at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous) in /_/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnectionFactory.cs:line 142
   at Microsoft.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(DbConnectionPoolKey key, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions) in /_/src/Microsoft.Data.SqlClient/netcore/src/Common/src/Microsoft/Data/ProviderBase/DbConnectionFactory.cs:line 216
   at Microsoft.Data.SqlClient.SqlConnection.ConnectionString_Set(DbConnectionPoolKey key) in /_/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnectionHelper.cs:line 72
   at Microsoft.Data.SqlClient.SqlConnection.set_ConnectionString(String value) in /_/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnection.cs:line 626
   at Microsoft.Data.SqlClient.SqlConnection..ctor(String connectionString) in /_/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnection.cs:line 159
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerConnection.CreateDbConnection()
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.get_DbConnection()
   at Microsoft.EntityFrameworkCore.Diagnostics.RelationalLoggerExtensions.MigrateUsingConnection(IDiagnosticsLogger`1 diagnostics, IMigrator migrator, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

Addition Details

Below code is my ApplicationDbContext which is in Domain Projects

using DigitalSociety.Data.Domain;
using Microsoft.EntityFrameworkCore;

namespace DigitalSociety.Data
{
    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
        {

        }
        public DbSet<House> Houses { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
        }
    }
}

and also i created ApplicationDbContextFactory

using Microsoft.EntityFrameworkCore.Design;
using Microsoft.EntityFrameworkCore;

namespace DigitalSociety.Data
{
    public class ApplicationDbContextFactory : IDesignTimeDbContextFactory<ApplicationDbContext>
    {
        public ApplicationDbContext CreateDbContext(string[] args)
        {
            var optionsBuilder = new DbContextOptionsBuilder<ApplicationDbContext>();
            optionsBuilder.UseSqlServer("DefaultConnection"); 

            return new ApplicationDbContext(optionsBuilder.Options);
        }
    }
}

Environment Details

Target Framework: .NET 8.0
SQL Server Version: SQL Server 2019
Operating System: Windows 11

[Rahulx1710]

Additionally same code works in version 6 but its not working in version 8

[ChrisJollyAU]

Think your problem is here optionsBuilder.UseSqlServer("DefaultConnection"); in the ApplicationDbContextFactory

Can see through the stack that there is the Microsoft.EntityFrameworkCore.Design calls as part of it so it is going through the design time code.

So from the above mentioned line, you are just giving EF Core a constant string with value "DefaultConnection". This is obviously not a normal connection string so it fails.

In your program.cs you do it a bit differently and actually look up the value options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));

Any thoughts on doing the same thing in design time?

[Rahulx1710]

ok got it,
now its work.
thank you

[Rahulx1710]

but I Don't understand this Why Its work in dotnet version 6 with out writing ApplicationDbContextFactory?