diff --git a/package.json b/package.json
index 936729c..ce1647d 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "scripts": {
-    "serve": "nodemon --exec \"vue-cli-service serve\"",
+    "serve": "NODE_ENV=development nodemon --exec \"vue-cli-service serve\"",
     "serve-prod": "NODE_ENV=production node src/server/index.js",
     "build": "KUZU_PATH=. vue-cli-service build",
     "lint": "vue-cli-service lint",
diff --git a/src/components/ShellView/ResultGraph.vue b/src/components/ShellView/ResultGraph.vue
index 981ffa1..c9cdb13 100644
--- a/src/components/ShellView/ResultGraph.vue
+++ b/src/components/ShellView/ResultGraph.vue
@@ -416,36 +416,38 @@ export default {
         for (let key in row) {
           switch (dataTypes[key]) {
             case DATA_TYPES.NODE: {
-              const node = row[key];
+              const node = { ...row[key] };
               processNode(node);
               break;
             }
             case DATA_TYPES.REL: {
-              const rel = row[key];
+              const rel = { ...row[key] };
               processRel(rel);
               break;
             }
             case DATA_TYPES.RECURSIVE_REL: {
-              const recursiveRel = row[key];
+              const recursiveRel = { ...row[key] };
               recursiveRel._nodes.forEach((node) => {
+                node = { ...node };
                 const nodeId = this.encodeNodeId(node._id);
                 if (nodes[nodeId]) {
                   return;
                 }
                 for (let key in node) {
-                  if (!node[key]) {
+                  if (node[key] === null || node[key] === undefined) {
                     delete node[key];
                   }
                 }
                 processNode(node);
               });
               recursiveRel._rels.forEach((rel) => {
+                rel = { ...rel };
                 const relId = this.encodeRelId(rel._src, rel._dst);
                 if (edges[relId]) {
                   return;
                 }
                 for (let key in rel) {
-                  if (!rel[key]) {
+                  if (rel[key] === null || rel[key] === undefined) {
                     delete rel[key];
                   }
                 }