Detect simple column mapping errors.

Author: bgrainger

src/MySqlConnector/MySql.Data.MySqlClient/MySqlBulkCopy.cs

@@ -159,7 +159,7 @@ private async ValueTask WriteToServerAsync(IOBehavior ioBehavior, CancellationTo
 			using (var reader = (MySqlDataReader) await cmd.ExecuteReaderAsync(CommandBehavior.SchemaOnly, ioBehavior, cancellationToken).ConfigureAwait(false))
 			{
 				var schema = reader.GetColumnSchema();
-				for (var i = 0; i < schema.Count; i++)
+				for (var i = 0; i < Math.Min(m_valuesEnumerator!.FieldCount, schema.Count); i++)
 				{
 					var destinationColumn = reader.GetName(i);
 					if (schema[i].DataTypeName == "BIT")
@@ -188,7 +188,7 @@ private async ValueTask WriteToServerAsync(IOBehavior ioBehavior, CancellationTo
 			}
 
 			// set columns and expressions from the column mappings
-			for (var i = 0; i < m_valuesEnumerator!.FieldCount; i++)
+			for (var i = 0; i < m_valuesEnumerator.FieldCount; i++)
 			{
 				var columnMapping = columnMappings.FirstOrDefault(x => x.SourceOrdinal == i);
 				if (columnMapping is null)
@@ -199,7 +199,7 @@ private async ValueTask WriteToServerAsync(IOBehavior ioBehavior, CancellationTo
 				else
 				{
 					if (columnMapping.DestinationColumn.Length == 0)
-						throw new InvalidOperationException("MySqlBulkCopyColumnMapping.DestinationName is not set.");
+						throw new InvalidOperationException("MySqlBulkCopyColumnMapping.DestinationName is not set for SourceOrdinal {0}".FormatInvariant(columnMapping.SourceOrdinal));
 					if (columnMapping.DestinationColumn[0] == '@')
 						bulkLoader.Columns.Add(columnMapping.DestinationColumn);
 					else
@@ -209,6 +209,12 @@ private async ValueTask WriteToServerAsync(IOBehavior ioBehavior, CancellationTo
 				}
 			}
 
+			foreach (var columnMapping in columnMappings)
+			{
+				if (columnMapping.SourceOrdinal < 0 || columnMapping.SourceOrdinal >= m_valuesEnumerator.FieldCount)
+					throw new InvalidOperationException("SourceOrdinal {0} is an invalid value".FormatInvariant(columnMapping.SourceOrdinal));
+			}
+
 			await bulkLoader.LoadAsync(ioBehavior, cancellationToken).ConfigureAwait(false);
 
 			if (closeConnection)

tests/SideBySide/BulkLoaderAsync.cs

@@ -499,8 +499,19 @@ public async Task BulkLoadDataTableWithTooLongData()
 			var bulkCopy = new MySqlBulkCopy(connection)
 			{
 				DestinationTableName = "bulk_load_data_table",
+				ColumnMappings =
+				{
+					new MySqlBulkCopyColumnMapping(0, "b"),
+				}
 			};
-			await Assert.ThrowsAsync<MySqlException>(async () => await bulkCopy.WriteToServerAsync(dataTable));
+			try
+			{
+				await bulkCopy.WriteToServerAsync(dataTable);
+				Assert.True(false, "Expected exception wasn't thrown");
+			}
+			catch (MySqlException ex) when (ex.InnerException?.InnerException is NotSupportedException)
+			{
+			}
 		}
 
 		[Theory]

tests/SideBySide/BulkLoaderSync.cs

@@ -822,8 +822,8 @@ public void BulkCopyColumnMappings()
 				Rows =
 				{
 					new object[] { 1, 100, "a", "A", new byte[] { 0x33, 0x30 } },
-					new object[] { 2, 200, "bb", "BB", new byte[] { 0x33, 0x31 }  },
-					new object[] { 3, 300, "ccc", "CCC", new byte[] { 0x33, 0x32 }  },
+					new object[] { 2, 200, "bb", "BB", new byte[] { 0x33, 0x31 } },
+					new object[] { 3, 300, "ccc", "CCC", new byte[] { 0x33, 0x32 } },
 				}
 			};
 
@@ -844,6 +844,80 @@ public void BulkCopyColumnMappings()
 			Assert.Equal(new byte[] { 0x33, 0x32 }, reader.GetValue(2));
 			Assert.False(reader.Read());
 		}
+
+		[Fact]
+		public void BulkCopyColumnMappingsInvalidSourceOrdinal()
+		{
+			using var connection = new MySqlConnection(GetLocalConnectionString());
+			connection.Open();
+			using (var cmd = new MySqlCommand(@"drop table if exists bulk_copy_column_mapping;
+				create table bulk_copy_column_mapping(intvalue int, `text` text, data blob);", connection))
+			{
+				cmd.ExecuteNonQuery();
+			}
+
+			var bulkCopy = new MySqlBulkCopy(connection)
+			{
+				DestinationTableName = "bulk_copy_column_mapping",
+				ColumnMappings =
+				{
+					new MySqlBulkCopyColumnMapping(6, "@val", "intvalue = @val + 1"),
+				},
+			};
+
+			var dataTable = new DataTable()
+			{
+				Columns =
+				{
+					new DataColumn("c1", typeof(int)),
+				},
+				Rows =
+				{
+					new object[] { 1 },
+					new object[] { 2 },
+					new object[] { 3 },
+				}
+			};
+
+			Assert.Throws<InvalidOperationException>(() => bulkCopy.WriteToServer(dataTable));
+		}
+
+		[Fact]
+		public void BulkCopyColumnMappingsInvalidDestinationColumn()
+		{
+			using var connection = new MySqlConnection(GetLocalConnectionString());
+			connection.Open();
+			using (var cmd = new MySqlCommand(@"drop table if exists bulk_copy_column_mapping;
+				create table bulk_copy_column_mapping(intvalue int, `text` text, data blob);", connection))
+			{
+				cmd.ExecuteNonQuery();
+			}
+
+			var bulkCopy = new MySqlBulkCopy(connection)
+			{
+				DestinationTableName = "bulk_copy_column_mapping",
+				ColumnMappings =
+				{
+					new MySqlBulkCopyColumnMapping { SourceOrdinal = 0 },
+				},
+			};
+
+			var dataTable = new DataTable()
+			{
+				Columns =
+				{
+					new DataColumn("c1", typeof(int)),
+				},
+				Rows =
+				{
+					new object[] { 1 },
+					new object[] { 2 },
+					new object[] { 3 },
+				}
+			};
+
+			Assert.Throws<InvalidOperationException>(() => bulkCopy.WriteToServer(dataTable));
+		}
 #endif
 
 		[Fact]