diff --git a/src/main/java/com/loafle/overflow/crawler/result/OFResultSetCol.java b/src/main/java/com/loafle/overflow/crawler/result/OFResultSetCol.java
index a3d5ecf..8aa0f5a 100644
--- a/src/main/java/com/loafle/overflow/crawler/result/OFResultSetCol.java
+++ b/src/main/java/com/loafle/overflow/crawler/result/OFResultSetCol.java
@@ -27,11 +27,14 @@ public class OFResultSetCol extends OFResultSet{
             this.meta.put(meta.get(indexI), indexI);
         }
 
-        for( int indexI = 0 ; indexI < arrayColumns.size(); ++indexI) {
-            this.meta.put(arrayColumns.get(indexI), indexI+ meta.size());
+        if( arrayColumns != null) {
+            for( int indexI = 0 ; indexI < arrayColumns.size(); ++indexI) {
+                this.meta.put(arrayColumns.get(indexI), indexI+ meta.size());
+            }
         }
 
 
+
     }
 
     public Map<String, String> parse() {
@@ -57,13 +60,16 @@ public class OFResultSetCol extends OFResultSet{
 
                 arrayValue.clear();
 
-                for(int indexL =0; indexL < arrayColumns.size(); ++indexL) {
-                    columnIdx = this.meta.get(arrayColumns.get(indexL));
+                if(arrayColumns != null ) {
+                    for(int indexL =0; indexL < arrayColumns.size(); ++indexL) {
+                        columnIdx = this.meta.get(arrayColumns.get(indexL));
 
-                    arrayValue.add(row.get(columnIdx));
+                        arrayValue.add(row.get(columnIdx));
+                    }
                 }
 
 
+
                 for(int indexK = 0 ; indexK < metrics.size(); ++indexK) {
 
                     metric = metrics.get(indexK);
@@ -83,6 +89,10 @@ public class OFResultSetCol extends OFResultSet{
 
     private String convertMetric(String metric, List<String> arrayValue) {
 
+        if(arrayValue == null || arrayValue.size() <= 0) {
+            return metric;
+        }
+
         String convertChar = "$";
         String convertStr = null;