Moved the creation of DbBatchCommands to the driver

Author: gliljas

src/NHibernate/AdoNet/DbBatchBatcher.cs

@@ -66,15 +66,8 @@ private void LogBatchCommand(DbCommand batchUpdate)
 
 		private void AddCommandToBatch(DbCommand batchUpdate)
 		{
-			var dbBatchCommand = _currentBatch.CreateBatchCommand();
-			dbBatchCommand.CommandText = batchUpdate.CommandText;
-			dbBatchCommand.CommandType = batchUpdate.CommandType;
-
-			foreach (var param in batchUpdate.Parameters)
-			{
-				dbBatchCommand.Parameters.Add(((ICloneable) param).Clone());
-			}
-
+			var dbBatchCommand = Driver.CreateDbBatchCommandFromDbCommand(_currentBatch, batchUpdate);
+			
 			_currentBatch.BatchCommands.Add(dbBatchCommand);
 		}
 

src/NHibernate/Driver/DbProviderFactoryDriveConnectionCommandProvider.cs

@@ -28,7 +28,7 @@ public DbCommand CreateCommand()
 #if NET6_0_OR_GREATER
 		public DbBatch CreateBatch() => dbProviderFactory.CreateBatch();
 
-		public bool CanCreateBatch => dbProviderFactory.CanCreateBatch && dbProviderFactory.CreateCommand() is ICloneable;
+		public bool CanCreateBatch => dbProviderFactory.CanCreateBatch && dbProviderFactory.CreateCommand().CreateParameter() is ICloneable;
 #endif
 	}
 }

src/NHibernate/Driver/DriverBase.cs

@@ -371,6 +371,25 @@ public virtual DbBatch CreateBatch()
 
 		public virtual bool CanCreateBatch => false;
 
+		/// <summary>
+		/// Override to use a custom mechanism to create a <see cref="DbBatchCommand"/> from a <see cref="DbCommand"/>.
+		/// The default implementation relies on the parameters implementing (and properly supporting) <see cref="System.ICloneable"/>
+		/// </summary>
+		/// <param name="dbBatch"></param>
+		/// <param name="dbCommand"></param>
+		/// <returns></returns>
+		public virtual DbBatchCommand CreateDbBatchCommandFromDbCommand(DbBatch dbBatch, DbCommand dbCommand)
+		{
+			var dbBatchCommand = dbBatch.CreateBatchCommand();
+			dbBatchCommand.CommandText = dbCommand.CommandText;
+			dbBatchCommand.CommandType = dbCommand.CommandType;
+			
+			foreach (var param in dbCommand.Parameters)
+			{
+				dbBatchCommand.Parameters.Add(((ICloneable) param).Clone());
+			}
+			return dbBatchCommand;
+		}
 
 #endif
 

src/NHibernate/Driver/IDriver.cs

@@ -165,11 +165,46 @@ public interface IDriver
 		DateTime MinDate { get; }
 
 #if NET6_0_OR_GREATER
+		/// <summary>
+		/// Create a <see cref="DbBatch"/>
+		/// </summary>
+		/// <returns></returns>
+		/// <exception cref="NotImplementedException"></exception>
 		DbBatch CreateBatch() => throw new NotImplementedException();
+		
+		/// <summary>
+		/// Can this driver create <see cref="DbBatch"/>es?
+		/// </summary>
 		bool CanCreateBatch => false;
 
+		/// <summary>
+		/// Make any adjustments to each <see cref="DbBatch"/> object before it is added to the batcher.
+		/// </summary>
+		/// <param name="dbBatch">The batch.</param>
+		/// <remarks>
+		/// This method should be executed before adding each single batch to the batcher.
+		/// If you have to adjust parameters values/type (when the command is fullfilled) this is a good place to do it.
+		/// </remarks>
 		void AdjustBatch(DbBatch dbBatch) => throw new NotImplementedException();
+
+		/// <summary>
+		/// Prepare the <paramref name="dbBatch" /> by calling <see cref="DbBatch.Prepare()" />.
+		/// May be a no-op if the driver does not support preparing commands, or for any other reason.
+		/// </summary>
+		/// <param name="dbBatch">The batch.</param>
 		void PrepareBatch(DbBatch dbBatch) => throw new NotImplementedException();
+
+		/// <summary>
+		/// Creates (clones) a <see cref="DbBatchCommand"/> from a <see cref="DbCommand"/>,
+		/// copying its <see cref="DbCommand.CommandText"/>, <see cref="DbCommand.CommandType"/>
+		/// and all its parameters.
+		/// The returned <see cref="DbBatchCommand"/> will not be added to <paramref name="dbBatch"/> 
+		/// </summary>
+		/// <param name="dbBatch"></param>
+		/// <param name="dbCommand"></param>
+		/// <returns></returns>
+		/// <exception cref="NotImplementedException"></exception>
+		DbBatchCommand CreateDbBatchCommandFromDbCommand(DbBatch dbBatch, DbCommand dbCommand) => throw new NotImplementedException();
 #endif
 	}
 }

src/NHibernate/Driver/ReflectionDriveConnectionCommandProvider.cs

@@ -25,7 +25,7 @@ public ReflectionDriveConnectionCommandProvider(System.Type connectionType, Syst
 			_canCreateBatch = new Lazy<bool>(() => {
 				using (var connection = CreateConnection())
 				{
-					return connection.CanCreateBatch && connection.CreateCommand() is ICloneable;
+					return connection.CanCreateBatch && connection.CreateCommand().CreateParameter() is ICloneable;
 				}
 			});
 #endif