code: public static void unRegisterFunction(Statement st, Function function) throws SQLException {
          String functionAlias = getStringProperty(function, Function.PROP_NAME);
          if(functionAlias.isEmpty()) {
              functionAlias = function.getClass().getSimpleName();
          }
          st.execute("DROP ALIAS IF EXISTS " + functionAlias);
      }
docs: Remove the specified function from the provided DataBase connection
  @param st Active statement
  @param function function to remove
  @throws SQLException