Stringsql="SELECT col_description(a.attrelid,a.attnum) as comment,format_type(a.atttypid,a.atttypmod) as type,a.attname as name, a.attnotnull as notnull FROM pg_class as c,pg_attribute as a where c.relname = '"
+tableName+"' and a.attrelid = c.oid and a.attnum>0";