Stored Procedure parameter name conflict since .NET 10 Preview

[mhartmair-cubido]

Bug description

Since upgrading to .NET 10 (Preview) calling stored procedures with params and than later introducing more parameters via LINQ leads to variable name conflict exceptions.

Your code

dbContext.Set<MyModel>()
  .FromSqlRaw("SELECT * FROM [dbo].[fn_MyFunction]({0})", parameter)
  .AsNoTracking()
  .Skip(pageIndex*pageSize)
  .Take(pageSize)
  .ToListAsync(cancellationToken);

Stack traces

Microsoft.Data.SqlClient.SqlException (0x80131904): The variable name '@p0' has already been declared. Variable names must be unique within a query batch or stored procedure.
         at Microsoft.Data.SqlClient.SqlCommand.<>c.<ExecuteDbDataReaderAsync>b__195_0(Task`1 result)
         at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
         at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
      --- End of stack trace from previous location ---
         at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
         at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
      --- End of stack trace from previous location ---
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
         at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToArrayAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
         ...[omitted]
Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
         at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
         at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|7_0(Endpoint endpoint, Task requestTask, ILogger logger)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddlewareImpl.<Invoke>g__Awaited|10_0(ExceptionHandlerMiddlewareImpl middleware, HttpContext context, Task task)
      Error Number:134,State:1,Class:15

Verbose output

 Microsoft.EntityFrameworkCore.Database.Command[20102]
      Failed executing DbCommand (24ms) [Parameters=[p0=NULL (Nullable = false), @p00='100', @p0='100'], CommandType='Text', CommandTimeout='30']
      SELECT 1--omitted
      FROM (
          SELECT * FROM [dbo].[fn_MyFunction](@p0)
      ) AS [c]
      ORDER BY [c].[Order] DESC
      OFFSET @p00 ROWS FETCH NEXT @p0 ROWS ONLY

EF Core version

10.0.0-rc.2.25502.107

Database provider

Microsoft.EntityFrameworkCore.SqlServer

Target framework

.NET 10.0

Operating system

Windows 11

IDE

Visual Studio 2026 11201.2

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• Regression in EF Core 10: SQL Parameter Name Collision on SQL Server due to Case-Insensitive Variable Names #36917

[roji]

I am unable to reproduce this with 10.0.0-rc.2.25502.107. Posting a partial fragment as above is very frequently insufficient - when posting a new issue, please always include a minimal, runnable program rather than a fragment or a textual description.

See below for the minimal repro I tried to use, based on your fragment above. When running this, I get the following SQL:

SELECT [b].[Id], [b].[Name]
FROM (
    SELECT * FROM fn_MyFunction(@p0)
) AS [b]
ORDER BY (SELECT 1)
OFFSET @p00 ROWS FETCH NEXT @p1 ROWS ONLY

While the parameter names aren't the prettiest, they're unique.

You can try to tweak my code below to make it fail; once you're able to show that, please post back here and I'll investigate.

Attempted repro

await using var context = new BlogContext();
await context.Database.EnsureDeletedAsync();
await context.Database.EnsureCreatedAsync();

var parameter = 42;
var pageIndex = 2;
var pageSize = 10;

_ = await context.Set<Blog>()
    .FromSqlRaw("SELECT * FROM fn_MyFunction({0})", parameter)
    .AsNoTracking()
    .Skip(pageIndex * pageSize)
    .Take(pageSize)
    .ToListAsync();

public class BlogContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseSqlServer("Server=localhost;Database=test;User=SA;Password=Abcd5678;Connect Timeout=60;ConnectRetryCount=0;Encrypt=false")
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();
}

public class Blog
{
    public int Id { get; set; }
    public string Name { get; set; }
}