upload.

src/select-null-value.js

+var _db = require("topsin.database");
+var _ = require("lodash");
+var _error = require("topsin.error");
+
+var DEMO_CONN = 'DEMO_CONN';
+_db.addConnection({
+  database_type: 'pg',
+  database_host: '139.196.104.13:5433',
+  database_name: 'TOPDFM_DEV_V6',
+  database_user: 'toplinker',
+  database_pwd: 'TopLinker0510'
+}, DEMO_CONN);
+
+try {
+    _db.query(DEMO_CONN, function(query){
+        var r = query.selectArrayMap("SELECT username, department_id FROM sys_user LIMIT 2", {});
+        if (query.lastError().isValid()) {
+            throw query.lastError().text();
+        }
+        print(JSON.stringify(r));
+        print(JSON.stringify(r, function(k, v){
+            return typeof v === 'undefined' ? null : v;
+          }));
+    });
+} catch (e) {
+    print(e);
+}