diff --git a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/db/vo/ModelCatalog.java b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/db/vo/ModelCatalog.java
index c1428a0..b46e984 100644
--- a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/db/vo/ModelCatalog.java
+++ b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/db/vo/ModelCatalog.java
@@ -30,6 +30,14 @@ public class ModelCatalog extends DefaultEntity {
         put("mc_parent_id", mcParentId);
     }
 
+    public String getLevelCode() {
+        return getStr("mc_level_code");
+    }
+
+    public void setLevelCode(String mcLevelCode) {
+        put("mc_level_code", mcLevelCode);
+    }
+
     public String getCode() {
         return getStr("mc_code");
     }
diff --git a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/mvc/service/TreeHelper.java b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/mvc/service/TreeHelper.java
index dee3937..63a1b21 100644
--- a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/mvc/service/TreeHelper.java
+++ b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/mvc/service/TreeHelper.java
@@ -66,7 +66,8 @@ public class TreeHelper<T extends DefaultEntity> {
 
     public List<T> getChildren(long id, Comparator<T> comparator) {
         Collection<T> set = cache.getListByKey(SwConsts.KEY_PARENT_ID, String.valueOf(id));
-        List<T> list = new ArrayList<>(set);
+
+        List<T> list = set == null ? new ArrayList<>(): new ArrayList<>(set);
         if (comparator != null)
         list.sort(comparator);
         return list;
diff --git a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/util/jackson/LongSerializer.java b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/util/jackson/LongSerializer.java
index 8dac914..d48d678 100644
--- a/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/util/jackson/LongSerializer.java
+++ b/smtweb-framework/sw-framework-core/src/main/java/cc/smtweb/framework/core/util/jackson/LongSerializer.java
@@ -13,7 +13,7 @@ public class LongSerializer extends JsonSerializer<Long> {
         if (value == null) {
             gen.writeNull();
         } else {
-            gen.writeNumber(value);
+            gen.writeString(String.valueOf(value));
         }
     }
 }
diff --git a/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/design/table/ModelCatalogTreeHandler.java b/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/design/table/ModelCatalogTreeHandler.java
index 52fe6a4..ba6680f 100644
--- a/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/design/table/ModelCatalogTreeHandler.java
+++ b/smtweb-system/sw-system-bpm/src/main/java/cc/smtweb/system/bpm/web/design/table/ModelCatalogTreeHandler.java
@@ -50,13 +50,13 @@ public class ModelCatalogTreeHandler extends AbstractTreeHandler<Object> {
 
         EntityDao<ModelCatalog> dao = DbEngine.getInstance().findDao(ModelCatalog.ENTITY_NAME);
         String text = "%" + params.readString("text") + "%";
-        List<ModelCatalog> list = dao.queryWhere(" where mc_prj_id=? and (mc_name like ? or mc_code like ?) order by mc_name", prj_id, text, text);
+        List<ModelCatalog> list = dao.queryWhere(" mc_prj_id=? and (mc_name like ? or mc_code like ?) order by mc_name", prj_id, text, text);
         listRet.addAll(list);
 
         switch (type) {
             case TYPE_TABLE:
                 EntityDao<ModelTable> tabledao = DbEngine.getInstance().findDao(ModelTable.class);
-                List<ModelTable> l = tabledao.queryWhere(" where tb_prj_id=? and (tb_name like ? or tb_title like ?) order by tb_name", prj_id, text, text);
+                List<ModelTable> l = tabledao.queryWhere(" tb_prj_id=? and (tb_name like ? or tb_title like ?) order by tb_name", prj_id, text, text);
                 listRet.addAll(l);
                 break;
             case TYPE_PAGE:
@@ -72,7 +72,7 @@ public class ModelCatalogTreeHandler extends AbstractTreeHandler<Object> {
         if (id > 0) {
             list = mcTreeHelper.getChildren(id, (o1, o2) -> CommUtil.chineseCompare(o1.getName(), o2.getName()));
         } else {
-            list = mcTreeHelper.getChildren(prj_id, (o1, o2) -> CommUtil.chineseCompare(o1.getName(), o2.getName()));
+            list = mcTreeHelper.getChildren(-1, (o1, o2) -> CommUtil.chineseCompare(o1.getName(), o2.getName()));
         }
 
         listRet.addAll(list);