diff --git a/FrmFlagDetail.cs b/FrmFlagDetail.cs
index d72eee9..cfd9769 100644
--- a/FrmFlagDetail.cs
+++ b/FrmFlagDetail.cs
@@ -8,6 +8,7 @@
 using System.Windows.Forms;
 using GeoScene.Globe;
 using System.Data.OracleClient;
+using System.Diagnostics;
 
 namespace Cyberpipe
 {
@@ -41,7 +42,13 @@
                 while (reader.Read())
                 {
                     objectIds = reader.GetString(0);
-                    objectTypeCodes = reader.GetString(1);
+                    if (reader.IsDBNull(1)){
+                        // 如果第二列为空
+                        objectTypeCodes = "";
+                    }
+                    else {
+                        objectTypeCodes = reader.GetString(1);
+                    }
                 }
             }
 
@@ -62,6 +69,7 @@
                 {
                     if (Utility.listPipelineType[i].code == codeTypes[n])
                     {
+                        // 根据类型编号得到类型名称
                         int index = this.dataGridViewX_markDetail.Rows.Add();
                         this.dataGridViewX_markDetail.Rows[index].Cells[0].Value = Utility.listPipelineType[i].type;
                         this.dataGridViewX_markDetail.Rows[index].Cells[1].Value = codeIds[n].ToString();