diff --git a/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java b/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java
index 05e0dc8..c3015c9 100644
--- a/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java
+++ b/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java
@@ -172,14 +172,14 @@ public class Sampler {
 				if (DBType.equals(POSTGRES)) {
 
 					// attribute = "CAST(" + listColumns.get(i) + " as text), ";
-					attribute = "CAST(" + listColumns.get(i)
+					attribute = "CAST(" + "\"" +listColumns.get(i)+ "\""
 							+ " as character varying(255)), ";
 
 					if (i == (listColumns.size() - 1)) {
 
 						// attribute = "CAST(" + listColumns.get(i) +
 						// " as text)";
-						attribute = "CAST(" + listColumns.get(i)
+						attribute = "CAST(" + "\"" + listColumns.get(i)+ "\""
 								+ " as character varying(255))";
 
 					}