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 1c1a9dc..b5aa8dd 100644
--- a/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java
+++ b/src/main/java/org/gcube/dataaccess/databases/sampler/Sampler.java
@@ -195,7 +195,7 @@ public class Sampler {
 						// " as CHAR CHARACTER SET utf8), ";
 						// attribute = "CONVERT(" + listColumns.get(i) +
 						// ", CHAR), ";
-						attribute = "CAST(" + listColumns.get(i)
+						attribute = "CAST(" + "`" +listColumns.get(i)+ "`"
 								+ " as CHAR CHARACTER SET utf8), ";
 
 						if (i == (listColumns.size() - 1)) {
@@ -206,14 +206,14 @@ public class Sampler {
 							// attribute = "CONVERT(" + listColumns.get(i) +
 							// ", BINARY)";
 
-							attribute = "CAST(" + listColumns.get(i)
+							attribute = "CAST(" + "`" +listColumns.get(i)+ "`"
 									+ " as CHAR CHARACTER SET utf8)";
 
 						}
 
 					} else {
 
-						attribute = "CAST(CAST(" + listColumns.get(i)
+						attribute = "CAST(CAST(" + "`" +listColumns.get(i)+ "`"
 								+ " as BINARY) as CHAR CHARACTER SET utf8), ";
 
 						if (i == (listColumns.size() - 1)) {
@@ -224,7 +224,7 @@ public class Sampler {
 							// attribute = "CONVERT(" + listColumns.get(i) +
 							// ", BINARY)";
 
-							attribute = "CAST(CAST(" + listColumns.get(i)
+							attribute = "CAST(CAST(" + "`" +listColumns.get(i)+ "`"
 									+ " as BINARY) as CHAR CHARACTER SET utf8)";
 
 						}