Fixed issue with long groups list

private-rows-extension/src/main/java/it/inaf/ia2/vollt/PrivateRowsQueryExecutor.java

@@ -14,11 +14,11 @@ public class PrivateRowsQueryExecutor extends QueryExecutor {
 
         if (jobOwner instanceof CustomJobOwner) {
             CustomJobOwner user = (CustomJobOwner) jobOwner;
-            statement.execute("SET my.tap_groups = \"{"
+            statement.execute("SET my.tap_groups = '{"
                     + String.join(",", user.getGroups().stream()
                             .map(g -> g.replace("'", "''"))
                             .collect(Collectors.toList()))
-                    + "}\"");
+                    + "}'");
         }
 
         return super.executeQuery(statement, sql, jobOwner);

private-rows-extension/src/test/java/it/inaf/ia2/vollt/PrivateRowsQueryExecutorTest.java

@@ -19,11 +19,11 @@ public class PrivateRowsQueryExecutorTest {
         Statement mockedStatement = mock(Statement.class);
         queryExecutor.executeQuery(mockedStatement, "", user);
 
-        verify(mockedStatement).execute(eq("SET my.tap_groups = \"{group1,group2}\""));
+        verify(mockedStatement).execute(eq("SET my.tap_groups = '{group1,group2}'"));
 
         user = new CustomJobOwner("anonymous", Arrays.asList());
         queryExecutor.executeQuery(mockedStatement, "", user);
 
-        verify(mockedStatement).execute(eq("SET my.tap_groups = \"{}\""));
+        verify(mockedStatement).execute(eq("SET my.tap_groups = '{}'"));
     }
 }