API review items (#28709)

* Append{Update,Delete}Command now accept a higher-level flag for
  adding a 1 constant to the RETURNING clause.
* Accept MaxBatchSize in the ReadModificationCommandBatch constructor

Part of #27588

src/EFCore.Relational/Update/AffectedCountModificationCommandBatch.cs

@@ -1,8 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Data;
-
 namespace Microsoft.EntityFrameworkCore.Update;
 
 /// <summary>
@@ -23,8 +21,9 @@ public abstract class AffectedCountModificationCommandBatch : ReaderModification
     ///     Creates a new <see cref="AffectedCountModificationCommandBatch" /> instance.
     /// </summary>
     /// <param name="dependencies">Service dependencies.</param>
-    protected AffectedCountModificationCommandBatch(ModificationCommandBatchFactoryDependencies dependencies)
-        : base(dependencies)
+    /// <param name="maxBatchSize">The maximum batch size. Defaults to 1000.</param>
+    protected AffectedCountModificationCommandBatch(ModificationCommandBatchFactoryDependencies dependencies, int? maxBatchSize = null)
+        : base(dependencies, maxBatchSize)
     {
     }
 

src/EFCore.Relational/Update/ReaderModificationCommandBatch.cs

@@ -33,7 +33,8 @@ public abstract class ReaderModificationCommandBatch : ModificationCommandBatch
     ///     Creates a new <see cref="ReaderModificationCommandBatch" /> instance.
     /// </summary>
     /// <param name="dependencies">Service dependencies.</param>
-    protected ReaderModificationCommandBatch(ModificationCommandBatchFactoryDependencies dependencies)
+    /// <param name="maxBatchSize">The maximum batch size. Defaults to 1000.</param>
+    protected ReaderModificationCommandBatch(ModificationCommandBatchFactoryDependencies dependencies, int? maxBatchSize = null)
     {
         Dependencies = dependencies;
 
@@ -42,6 +43,8 @@ protected ReaderModificationCommandBatch(ModificationCommandBatchFactoryDependen
         UpdateSqlGenerator = dependencies.UpdateSqlGenerator;
         UpdateSqlGenerator.AppendBatchHeader(SqlBuilder);
         _batchHeaderLength = SqlBuilder.Length;
+
+        MaxBatchSize = maxBatchSize ?? 1000;
     }
 
     /// <summary>
@@ -62,8 +65,7 @@ protected ReaderModificationCommandBatch(ModificationCommandBatchFactoryDependen
     /// <summary>
     ///     The maximum number of <see cref="ModificationCommand"/> instances that can be added to a single batch.
     /// </summary>
-    protected virtual int MaxBatchSize
-        => 1000;
+    protected virtual int MaxBatchSize { get; }
 
     /// <summary>
     ///     Gets the command text builder for the commands in the batch.

src/EFCore.Relational/Update/SingularModificationCommandBatch.cs

@@ -23,13 +23,7 @@ public class SingularModificationCommandBatch : AffectedCountModificationCommand
     /// </summary>
     /// <param name="dependencies">Service dependencies.</param>
     public SingularModificationCommandBatch(ModificationCommandBatchFactoryDependencies dependencies)
-        : base(dependencies)
+        : base(dependencies, maxBatchSize: 1)
     {
     }
-
-    /// <summary>
-    ///     The maximum number of <see cref="ModificationCommand"/> instances that can be added to a single batch; always returns 1.
-    /// </summary>
-    protected override int MaxBatchSize
-        => 1;
 }

src/EFCore.Relational/Update/UpdateSqlGenerator.cs

@@ -134,7 +134,7 @@ protected virtual ResultSetMapping AppendUpdateReturningOperation(
 
         AppendUpdateCommand(
             commandStringBuilder, name, schema, writeOperations, readOperations, conditionOperations,
-            additionalReadValues: readOperations.Count == 0 ? "1" : null);
+            appendReturningOneClause: readOperations.Count == 0);
 
         return ResultSetMapping.LastInResultSet;
     }
@@ -175,7 +175,7 @@ protected virtual ResultSetMapping AppendDeleteReturningOperation(
         requiresTransaction = false;
 
         AppendDeleteCommand(
-            commandStringBuilder, name, schema, Array.Empty<IColumnModification>(), conditionOperations, additionalReadValues: "1");
+            commandStringBuilder, name, schema, Array.Empty<IColumnModification>(), conditionOperations, appendReturningOneClause: true);
 
         return ResultSetMapping.LastInResultSet;
     }
@@ -211,19 +211,19 @@ protected virtual void AppendInsertCommand(
     /// <param name="writeOperations">The operations for each column.</param>
     /// <param name="readOperations">The operations for column values to be read back.</param>
     /// <param name="conditionOperations">The operations used to generate the <c>WHERE</c> clause for the update.</param>
-    /// <param name="additionalReadValues">Additional values to be read back.</param>
+    /// <param name="appendReturningOneClause">Whether to append an additional constant of 1 to be read back.</param>
     protected virtual void AppendUpdateCommand(
         StringBuilder commandStringBuilder,
         string name,
         string? schema,
         IReadOnlyList<IColumnModification> writeOperations,
         IReadOnlyList<IColumnModification> readOperations,
         IReadOnlyList<IColumnModification> conditionOperations,
-        string? additionalReadValues = null)
+        bool appendReturningOneClause = false)
     {
         AppendUpdateCommandHeader(commandStringBuilder, name, schema, writeOperations);
         AppendWhereClause(commandStringBuilder, conditionOperations);
-        AppendReturningClause(commandStringBuilder, readOperations, additionalReadValues);
+        AppendReturningClause(commandStringBuilder, readOperations, appendReturningOneClause ? "1" : null);
         commandStringBuilder.AppendLine(SqlGenerationHelper.StatementTerminator);
     }
 
@@ -235,18 +235,18 @@ protected virtual void AppendUpdateCommand(
     /// <param name="schema">The table schema, or <see langword="null" /> to use the default schema.</param>
     /// <param name="readOperations">The operations for column values to be read back.</param>
     /// <param name="conditionOperations">The operations used to generate the <c>WHERE</c> clause for the delete.</param>
-    /// <param name="additionalReadValues">Additional values to be read back.</param>
+    /// <param name="appendReturningOneClause">Whether to append an additional constant of 1 to be read back.</param>
     protected virtual void AppendDeleteCommand(
         StringBuilder commandStringBuilder,
         string name,
         string? schema,
         IReadOnlyList<IColumnModification> readOperations,
         IReadOnlyList<IColumnModification> conditionOperations,
-        string? additionalReadValues = null)
+        bool appendReturningOneClause = false)
     {
         AppendDeleteCommandHeader(commandStringBuilder, name, schema);
         AppendWhereClause(commandStringBuilder, conditionOperations);
-        AppendReturningClause(commandStringBuilder, readOperations, additionalReadValues);
+        AppendReturningClause(commandStringBuilder, readOperations, appendReturningOneClause ? "1" : null);
         commandStringBuilder.AppendLine(SqlGenerationHelper.StatementTerminator);
     }
 
@@ -478,7 +478,7 @@ protected virtual void AppendReturningClause(
                     commandStringBuilder.Append(", ");
                 }
 
-                commandStringBuilder.Append(additionalValues);
+                commandStringBuilder.Append("1");
             }
         }
     }

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

@@ -29,8 +29,9 @@ public class SqlServerModificationCommandBatch : AffectedCountModificationComman
     public SqlServerModificationCommandBatch(
         ModificationCommandBatchFactoryDependencies dependencies,
         int maxBatchSize)
-        : base(dependencies)
-        => MaxBatchSize = maxBatchSize;
+        : base(dependencies, maxBatchSize)
+    {
+    }
 
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -41,14 +42,6 @@ public SqlServerModificationCommandBatch(
     protected new virtual ISqlServerUpdateSqlGenerator UpdateSqlGenerator
         => (ISqlServerUpdateSqlGenerator)base.UpdateSqlGenerator;
 
-    /// <summary>
-    ///     The maximum number of <see cref="ModificationCommand"/> instances that can be added to a single batch.
-    /// </summary>
-    /// <remarks>
-    ///     For SQL Server, this is 42 by default, and cannot exceed 1000.
-    /// </remarks>
-    protected override int MaxBatchSize { get; }
-
     /// <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

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

@@ -126,11 +126,11 @@ protected override void AppendUpdateCommand(
         IReadOnlyList<IColumnModification> writeOperations,
         IReadOnlyList<IColumnModification> readOperations,
         IReadOnlyList<IColumnModification> conditionOperations,
-        string? additionalReadValues = null)
+        bool appendReturningOneClause = false)
     {
         // In SQL Server the OUTPUT clause is placed differently (before the WHERE instead of at the end)
         AppendUpdateCommandHeader(commandStringBuilder, name, schema, writeOperations);
-        AppendOutputClause(commandStringBuilder, readOperations, additionalReadValues);
+        AppendOutputClause(commandStringBuilder, readOperations, appendReturningOneClause ? "1" : null);
         AppendWhereClause(commandStringBuilder, conditionOperations);
         commandStringBuilder.AppendLine(SqlGenerationHelper.StatementTerminator);
     }
@@ -166,11 +166,11 @@ protected override void AppendDeleteCommand(
         string? schema,
         IReadOnlyList<IColumnModification> readOperations,
         IReadOnlyList<IColumnModification> conditionOperations,
-        string? additionalReadValues = null)
+        bool appendReturningOneClause = false)
     {
         // In SQL Server the OUTPUT clause is placed differently (before the WHERE instead of at the end)
         AppendDeleteCommandHeader(commandStringBuilder, name, schema);
-        AppendOutputClause(commandStringBuilder, readOperations, additionalReadValues);
+        AppendOutputClause(commandStringBuilder, readOperations, appendReturningOneClause ? "1" : null);
         AppendWhereClause(commandStringBuilder, conditionOperations);
         commandStringBuilder.AppendLine(SqlGenerationHelper.StatementTerminator);
     }