ORA-00942 Table or View Does Not Exist - Identify target table

During the installation of a third party application which uses Oracle Database, I found the following error in server log:

ORA-00942: table or view does not exist
00942. 00000 -  "table or view does not exist"

The error was clear, the application was trying to execute an SQL statement against a table that was not in database, or the user did not have permissions. But, which table or view was that?

In order to discover the SQL the client was invoking I found this post: https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:2975793633621#284628100346267414. In my post I´ll just refactor it in order to easy understanding.

The idea behind of this is to register a trigger for server error 942, obtain  context information and the sql being executed, and save all this info in other table. The complete code is as follow:

-- Table to store errors
create table ERROR942 (id number, 
    "time" timestamp,
    "event" varchar(100), 
    "user" varchar(100),
    "server_error" varchar2(4000),
    "sql" varchar2(4000) );

-- Sequence to generate the table id
create sequence SEQ_ERROR942;


-- Trigger to insert errors in table
create or replace trigger TGR_SERVER942
after servererror on database
declare
   l_sql_text ora_name_list_t;
   full_sql varchar2(4000);
   l_n number;
begin
    if ( is_servererror(942) )
    then        
        full_sql := '';
        l_n := ora_sql_txt( l_sql_text );
        for i in 1 .. l_n
        loop
           full_sql := full_sql || l_sql_text(i);
        end loop;
        
         insert into ERROR942 values (SEQ_ERROR942.nextval, current_date, ora_sysevent, ora_login_user,  ora_server_error(1), full_sql);
    end if;
end;

commit;

The main aspects here are:

• We create ERROR942 table in order to store all errors
• We create SEQ_ERROR942 in order to generate the previous table ids
• We create TGR_SERVER942 trigger in order to capture server errors and store then in the table. 

You can test the solution as follow:

select * from UNEXIST_TABLE;

select * ERROR942;