MAINT: reintroduce workaround for empty string

src/caosadvancedtools/crawler.py

@@ -255,10 +255,7 @@ class Crawler(object):
             query_string += " WITH "
 
             for p in entity.get_properties():
-                if p.value == "":
-                    query_string += (" NOT '" + p.name + "' AND ")
-                else:
-                    query_string += ("'" + p.name + "'='" + str(get_value(p))
+                query_string += ("'" + p.name + "'='" + str(get_value(p))
                                      + "' AND ")
             # remove the last AND
             query_string = query_string[:-4]