Fix: support xml type for bulkcopy

Author: dlapko

bulkcopy.go

@@ -82,6 +82,13 @@ func (b *Bulk) sendBulkCommand(ctx context.Context) (err error) {
 			}
 		}
 		if bulkCol != nil {
+			// Note that for INSERT BULK operations, XMLTYPE is to be sent as NVARCHAR(N) or NVARCHAR(MAX) data type.
+			// An error is produced if XMLTYPE is specified.
+			//
+			// https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-tds/ab4a7d62-cd1f-4db1-b67d-ecae58f493e3
+			if bulkCol.ti.TypeId == typeXml {
+				bulkCol.ti.TypeId = typeNVarChar
+			}
 
 			if bulkCol.ti.TypeId == typeUdt {
 				//send udt as binary
@@ -617,7 +624,6 @@ func (b *Bulk) makeParam(val DataValue, col columnStruct) (res param, err error)
 			err = fmt.Errorf("mssql: invalid type for Guid column: %T %s", val, val)
 			return
 		}
-
 	default:
 		err = fmt.Errorf("mssql: type %x not implemented", col.ti.TypeId)
 	}

bulkcopy_test.go

@@ -202,6 +202,8 @@ func testBulkcopy(t *testing.T, guidConversion bool) {
 		{"test_intnvarchar", 1234, "1234"},
 		{"test_image", []byte("1"), nil},
 		{"test_imagen", nil, nil},
+		{"test_xml", "<root><child>value</child></root>", nil},
+		{"test_xmln", nil, nil},
 	}
 
 	columns := make([]string, len(testValues))
@@ -417,7 +419,8 @@ func setupTable(ctx context.Context, t *testing.T, conn *sql.Conn, tableName str
 	[test_intf32] [int] NULL,
 	[test_geom] [geometry] NULL,
 	[test_geog] [geography] NULL,
-	[text_xml] [xml] NULL,
+	[test_xml] [xml] NOT NULL,
+	[test_xmln] [xml] NULL,
 	[test_uniqueidentifier] [uniqueidentifier] NULL,
 	[test_nulluniqueidentifier] [uniqueidentifier] NULL,
 	[test_decimal_18_0] [decimal](18, 0) NULL,