sql - Oracle: query against value of user defined type -

I have a user defined type:

  Type the object as my_message_type Whistler 2 (50), payload clobe);   
 I have put a program in the program that SQL Developer translates the inserted object as:  
  SYNESSO.MY_MESSAGE_TYPE ('abcdefgh', 'oracle .sql.CLOB @ 1dae16a ')   
 How can query against this data using SQL? For example, the following is intuitive: Select  
  from count_ (1) to table_of_my_messages where user_data.relatedid = 'abcdefgh';   
 but the result is  ORA-00904: "USER_DATA". "RELATEDID": invalid identifier .  
 Then I have to create the right syntax for creating the message type and using similarity check but how to prepare an example of type with some fields that match  any  Go:  
  Select from table_of_my_messages * where user_data = my_message_type ('abcdefgh', *); - ORA-00936: unavailable expression * select from table_of_my_messages * where user_data = my_message_type ('abcdefgh'); - ORA-02315: Choose the wrong number of arguments for the default constructor * to select table_of_my_messages where user_data = my_message_type ('abcdefgh',?); - Index: 1    
 
 
 Intuitive version is almost almost the right thing. I only need to have the nickname of the table to work ...  
  select the mean number from the table_of_i_mail (1) where m.user_data.relatedid = 'abcdefgh';