[release/7.0] Fix SQL Server result mapping for bulk insert (#29565)

src/EFCore.SqlServer/Update/Internal/SqlServerModificationCommandBatch.cs

@@ -25,6 +25,9 @@ public class SqlServerModificationCommandBatch : AffectedCountModificationComman
 
     private readonly List<IReadOnlyModificationCommand> _pendingBulkInsertCommands = new();
 
+    private static readonly bool QuirkEnabled29502
+        = AppContext.TryGetSwitch("Microsoft.EntityFrameworkCore.Issue29502", out var enabled) && enabled;
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
@@ -116,9 +119,21 @@ private void ApplyPendingBulkInsertCommands()
             ResultSetMappings.Add(resultSetMapping);
         }
 
-        if (resultSetMapping != ResultSetMapping.NoResults)
+        // All result mappings are marked as "not last", mark the last one as "last".
+        if (QuirkEnabled29502)
+        {
+            if (resultSetMapping != ResultSetMapping.NoResults)
+            {
+                ResultSetMappings[^1] = ResultSetMapping.LastInResultSet;
+            }
+        }
+        else
         {
-            ResultSetMappings[^1] = ResultSetMapping.LastInResultSet;
+            if (resultSetMapping.HasFlag(ResultSetMapping.HasResultRow))
+            {
+                ResultSetMappings[^1] &= ~ResultSetMapping.NotLastInResultSet;
+                ResultSetMappings[^1] |= ResultSetMapping.LastInResultSet;
+            }
         }
     }
 

test/EFCore.Relational.Specification.Tests/Update/NonSharedModelUpdatesTestBase.cs

@@ -12,8 +12,7 @@ protected override string StoreName
         => "NonSharedModelUpdatesTestBase";
 
     [ConditionalTheory] // Issue #29356
-    [InlineData(false)]
-    [InlineData(true)]
+    [MemberData(nameof(IsAsyncData))]
     public virtual async Task Principal_and_dependent_roundtrips_with_cycle_breaking(bool async)
     {
         var contextFactory = await InitializeAsync<DbContext>(

test/EFCore.SqlServer.FunctionalTests/EFCore.SqlServer.FunctionalTests.csproj

@@ -49,6 +49,9 @@
     <None Update="SqlAzure\adventureworks.sql">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="Update\Issue29502.sql">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="config.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>

test/EFCore.SqlServer.FunctionalTests/TestUtilities/SqlServerTestStore.cs

@@ -29,8 +29,12 @@ public static SqlServerTestStore GetOrCreateInitialized(string name)
     public static SqlServerTestStore GetOrCreateWithInitScript(string name, string initScript)
         => new(name, initScript: initScript);
 
-    public static SqlServerTestStore GetOrCreateWithScriptPath(string name, string scriptPath, bool? multipleActiveResultSets = null)
-        => new(name, scriptPath: scriptPath, multipleActiveResultSets: multipleActiveResultSets);
+    public static SqlServerTestStore GetOrCreateWithScriptPath(
+        string name,
+        string scriptPath,
+        bool? multipleActiveResultSets = null,
+        bool shared = true)
+        => new(name, scriptPath: scriptPath, multipleActiveResultSets: multipleActiveResultSets, shared: shared);
 
     public static SqlServerTestStore Create(string name, bool useFileName = false)
         => new(name, useFileName, shared: false);

test/EFCore.SqlServer.FunctionalTests/Update/NonSharedModelUpdatesSqlServerTest.cs

@@ -84,6 +84,52 @@ OUTPUT 1
 """);
     }
 
+    [ConditionalFact] // Issue #29502
+    public virtual async Task Bulk_insert_result_set_mapping()
+    {
+        var contextFactory = await InitializeAsync<DbContext>(
+            onModelCreating: mb =>
+            {
+                mb.Entity<User>().ToTable("Users");
+                mb.Entity<DailyDigest>().ToTable("DailyDigests");
+            },
+            createTestStore: () => SqlServerTestStore.GetOrCreateWithScriptPath(
+                "Issue29502",
+                Path.Combine("Update", "Issue29502.sql"),
+                shared: false));
+
+        await ExecuteWithStrategyInTransactionAsync(
+            contextFactory,
+            async context =>
+            {
+                var digests = await context.Set<User>()
+                    .OrderBy(u => u.TimeCreatedUtc)
+                    .Take(23)
+                    .Select(u => new DailyDigest { User = u })
+                    .ToListAsync();
+
+                foreach (var digest in digests)
+                {
+                    context.Set<DailyDigest>().Add(digest);
+                }
+
+                await context.SaveChangesAsync();
+            });
+    }
+
+    public class User
+    {
+        public string Id { get; set; } = null!;
+        public DateTime TimeCreatedUtc { get; set; }
+        public ICollection<DailyDigest> DailyDigests { get; set; } = null!;
+    }
+
+    public class DailyDigest
+    {
+        public int Id { get; set; }
+        public User User { get; set; }
+    }
+
     private void AssertSql(params string[] expected)
         => TestSqlLoggerFactory.AssertBaseline(expected);
 

test/EFCore.Sqlite.FunctionalTests/Update/NonSharedModelUpdatesSqliteTest.cs

@@ -3,7 +3,7 @@
 
 namespace Microsoft.EntityFrameworkCore.Update;
 
-public class NonSharedModelUpdatesSqlServerTest : NonSharedModelUpdatesTestBase
+public class NonSharedModelUpdatesSqliteTest : NonSharedModelUpdatesTestBase
 {
     public override async Task Principal_and_dependent_roundtrips_with_cycle_breaking(bool async)
     {