EF Core 10: InvalidOperationException doing primitive list join when list is empty

[EvanChrisp]

Bug description

In EF Core 10 doing Join/GroupJoin/LeftJoin with an empty primitive list throws the error below. I have confirmed this query works in EF Core 8 and 9.

Your code

using Microsoft.EntityFrameworkCore;

namespace EFGetStarted;

public class BloggingContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }
    public DbSet<Post> Posts { get; set; }

    public string DbPath { get; }

    public BloggingContext()
    {
        var folder = Environment.SpecialFolder.LocalApplicationData;
        var path = Environment.GetFolderPath(folder);
        DbPath = System.IO.Path.Join(path, "blogging.db");
    }

    // The following configures EF to create a Sqlite database file in the
    // special "local" folder for your platform.
    protected override void OnConfiguring(DbContextOptionsBuilder options)
        => options.UseSqlite($"Data Source={DbPath}");
}

public class Blog
{
    public int BlogId { get; set; }
    public string Url { get; set; }

    public List<Post> Posts { get; } = new();
}

public class Post
{
    public int PostId { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }

    public int BlogId { get; set; }
    public Blog Blog { get; set; }
}

public class Program
{
    public static async Task<int> Main(string[] args)
    {
        using var db = new BloggingContext();

        List<int> ids = [];
        var blogs = await db.Blogs.Join(ids, b => b.BlogId, ids => ids, (b, ids) => b).ToListAsync();

        return 0;
    }
}

Stack traces

System.InvalidOperationException
  HResult=0x80131509
  Message=Empty collections are not supported as inline query roots.
  Source=Microsoft.EntityFrameworkCore.Relational
  StackTrace:
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateValues(ValuesExpression valuesExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitValues(ValuesExpression valuesExpression)
   at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Sqlite.Query.Internal.SqliteQuerySqlGenerator.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitInnerJoin(InnerJoinExpression innerJoinExpression)
   at Microsoft.EntityFrameworkCore.Query.SqlExpressionVisitor.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Sqlite.Query.Internal.SqliteQuerySqlGenerator.VisitExtension(Expression extensionExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.<GenerateFrom>b__50_0(TableExpressionBase e)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateList[T](IReadOnlyList`1 items, Action`1 generationAction, Action`1 joinAction)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateFrom(SelectExpression selectExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.VisitSelect(SelectExpression selectExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GenerateRootCommand(Expression queryExpression)
   at Microsoft.EntityFrameworkCore.Query.QuerySqlGenerator.GetCommand(Expression queryExpression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalCommandCache.GetRelationalCommandTemplate(Dictionary`2 parameters)
   at Microsoft.EntityFrameworkCore.Internal.RelationalCommandResolverExtensions.RentAndPopulateRelationalCommand(RelationalCommandResolver relationalCommandResolver, RelationalQueryContext queryContext)
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.<InitializeReaderAsync>d__21.MoveNext()
   at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.<MoveNextAsync>d__20.MoveNext()
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.<ToListAsync>d__67`1.MoveNext()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.<ToListAsync>d__67`1.MoveNext()
   at EFGetStarted.Program.<Main>d__0.MoveNext() in X:\source\EFGetStarted\EFGetStarted\Program.cs:line 50

Verbose output

EF Core version

10.0.0

Database provider

Microsoft.EntityFrameworkCore.Sqlite, Microsoft.EntityFrameworkCore.SqlServer

Target framework

.NET 10

Operating system

No response

IDE

No response

[MihuBot]

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

• Did Contains stop working on empty list in EF Core 8? #32375

[roji]

Confirmed regression in 10.0.

Minimal repro

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

List<int> ids = [];

// Works, translate to WHERE 0 = 1
// _ = await context.Blogs.Where(b => ids.Contains(b.Id)).ToListAsync();

// Fails: Empty collections are not supported as inline query roots.
_ = await context.Blogs.Join(ids, b => b.Id, ids => ids, (b, ids) => b).ToListAsync();

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

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseSqlServer(Environment.GetEnvironmentVariable("Test__SqlServer__DefaultConnection"))
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();
}

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

[SpaceOgre]

This is also a problem when using .All()

List<int> ids = [];
context.Contracts
    .Where(c => ids .All(paramId => c.ParameterConnections.Any(pc => pc.ParameterId == paramId)))

This gives the same exception:

Empty collections are not supported as inline query roots

But if I add a check in the where statement, like this:

List<int> ids = [];
context.Contracts
    .Where(c => ids.Count == 0 || ids .All(paramId => c.ParameterConnections.Any(pc => pc.ParameterId == paramId)))

Then it works and no exception is recived.