diff --git a/test/EFCore.Relational.Specification.Tests/Query/ToSqlQueryTestBase.cs b/test/EFCore.Relational.Specification.Tests/Query/ToSqlQueryTestBase.cs
new file mode 100644
index 00000000000..d755a6b4c25
--- /dev/null
+++ b/test/EFCore.Relational.Specification.Tests/Query/ToSqlQueryTestBase.cs
@@ -0,0 +1,130 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable enable
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public abstract class ToSqlQueryTestBase : NonSharedModelTestBase
+{
+    protected override string StoreName
+        => "ToSqlQueryTests";
+
+    [ConditionalTheory]
+    [MemberData(nameof(IsAsyncData))] // Issue #27629
+    public virtual async Task Entity_type_with_navigation_mapped_to_SqlQuery(bool async)
+    {
+        var contextFactory = await InitializeAsync<Context27629>(seed: c =>
+        {
+            var author = new Author { Name = "Toast", Posts = { new() { Title = "Sausages of the world!"} } };
+            c.Add(author);
+            c.SaveChanges();
+
+            var postStat = new PostStat { Count = 10, Author = author };
+            author.PostStat = postStat;
+            c.Add(postStat);
+            c.SaveChanges();
+        });
+
+        using var context = contextFactory.CreateContext();
+
+        var authors = await
+            (from o in context.Authors
+             select new
+             {
+                 Author = o,
+                 PostCount = o.PostStat!.Count
+             }).ToListAsync();
+
+        Assert.Single(authors);
+        Assert.Equal("Toast", authors[0].Author.Name);
+        Assert.Equal(10, authors[0].PostCount);
+    }
+
+    protected class Context27629 : DbContext
+    {
+        public Context27629(DbContextOptions options)
+            : base(options)
+        {
+        }
+
+        public DbSet<Author> Authors
+            => Set<Author>();
+
+        public DbSet<Post> Posts
+            => Set<Post>();
+
+        public DbSet<PostStat> PostStats
+            => Set<PostStat>();
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<Author>(
+                builder =>
+                {
+                    builder.ToTable("Authors");
+                    builder.Property(o => o.Name).HasMaxLength(50);
+                });
+
+            modelBuilder.Entity<Post>(
+                builder =>
+                {
+                    builder.ToTable("Posts");
+                    builder.Property(o => o.Title).HasMaxLength(50);
+                    builder.Property(o => o.Content).HasMaxLength(500);
+
+                    builder
+                        .HasOne(o => o.Author)
+                        .WithMany(o => o.Posts)
+                        .HasForeignKey(o => o.AuthorId)
+                        .OnDelete(DeleteBehavior.ClientCascade);
+                });
+
+            modelBuilder.Entity<PostStat>(
+                builder =>
+                {
+                    builder
+                        .ToSqlQuery("SELECT * FROM PostStats")
+                        .HasKey(o => o.AuthorId);
+
+                    builder
+                        .HasOne(o => o.Author)
+                        .WithOne().HasForeignKey<PostStat>(o => o.AuthorId)
+                        .OnDelete(DeleteBehavior.ClientCascade);
+                });
+        }
+    }
+
+    protected class Author
+    {
+        public long Id { get; set; }
+        public string Name { get; set; } = null!;
+        public List<Post> Posts { get; } = new();
+        public PostStat? PostStat { get; set; }
+    }
+
+    protected class Post
+    {
+        public long Id { get; set; }
+        public long AuthorId { get; set; }
+        public Author Author { get; set; } = null!;
+        public string? Title { get; set; }
+        public string? Content { get; set; }
+    }
+
+    protected class PostStat
+    {
+        public long AuthorId { get; set; }
+        public Author Author { get; set; } = null!;
+        public long? Count { get; set; }
+    }
+
+    public void UseTransaction(DatabaseFacade facade, IDbContextTransaction transaction)
+        => facade.UseTransaction(transaction.GetDbTransaction());
+
+    protected TestSqlLoggerFactory TestSqlLoggerFactory
+        => (TestSqlLoggerFactory)ListLoggerFactory;
+
+    protected void ClearLog()
+        => TestSqlLoggerFactory.Clear();
+}
diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/ToSqlQuerySqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Query/ToSqlQuerySqlServerTest.cs
new file mode 100644
index 00000000000..73362d151c3
--- /dev/null
+++ b/test/EFCore.SqlServer.FunctionalTests/Query/ToSqlQuerySqlServerTest.cs
@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public class ToSqlQuerySqlServerTest : ToSqlQueryTestBase
+{
+    protected override ITestStoreFactory TestStoreFactory
+        => SqlServerTestStoreFactory.Instance;
+
+    [ConditionalFact]
+    public virtual void Check_all_tests_overridden()
+        => TestHelpers.AssertAllMethodsOverridden(GetType());
+
+    public override async Task Entity_type_with_navigation_mapped_to_SqlQuery(bool async)
+    {
+        await base.Entity_type_with_navigation_mapped_to_SqlQuery(async);
+
+        AssertSql(
+            @"SELECT [a].[Id], [a].[Name], [a].[PostStatAuthorId], [m].[Count] AS [PostCount]
+FROM [Authors] AS [a]
+LEFT JOIN (
+    SELECT * FROM PostStats
+) AS [m] ON [a].[PostStatAuthorId] = [m].[AuthorId]");
+    }
+
+    private void AssertSql(params string[] expected)
+        => TestSqlLoggerFactory.AssertBaseline(expected);
+}
diff --git a/test/EFCore.Sqlite.FunctionalTests/Query/ToSqlQuerySqliteTest.cs b/test/EFCore.Sqlite.FunctionalTests/Query/ToSqlQuerySqliteTest.cs
new file mode 100644
index 00000000000..7dab8a91b7d
--- /dev/null
+++ b/test/EFCore.Sqlite.FunctionalTests/Query/ToSqlQuerySqliteTest.cs
@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Query;
+
+public class ToSqlQuerySqliteTest : ToSqlQueryTestBase
+{
+    protected override ITestStoreFactory TestStoreFactory
+        => SqliteTestStoreFactory.Instance;
+
+    [ConditionalFact]
+    public virtual void Check_all_tests_overridden()
+        => TestHelpers.AssertAllMethodsOverridden(GetType());
+
+    public override async Task Entity_type_with_navigation_mapped_to_SqlQuery(bool async)
+    {
+        await base.Entity_type_with_navigation_mapped_to_SqlQuery(async);
+
+        AssertSql(
+            @"SELECT ""a"".""Id"", ""a"".""Name"", ""a"".""PostStatAuthorId"", ""m"".""Count"" AS ""PostCount""
+FROM ""Authors"" AS ""a""
+LEFT JOIN (
+    SELECT * FROM PostStats
+) AS ""m"" ON ""a"".""PostStatAuthorId"" = ""m"".""AuthorId""");
+    }
+
+    private void AssertSql(params string[] expected)
+        => TestSqlLoggerFactory.AssertBaseline(expected);
+}