May be I am misunderstanding your question but if all you want is to get a database error why can't you change your code to provide incorrect SQL syntax or an incorrect parameter to a procedure or whatever. If you cannot change your code can you lock a table the code uses and wait for a lock timeout? This seems so straight forward I'm sure you must mean something else. If so what kind of "database" error do you need?

Rather than locking a table (very unusual in Oracle), you can try simply misspelling a column name in your SQL statement. Oracle's compiler will throw an error for that.

select fred from global_name
       *
ERROR at line 1:
ORA-00904: "FRED": invalid identifier
[download]

Thanks for your reply. But i thing is, my code has to run for some extent then it has to throw DB error. So that only i can test my code for particular case. Tell me how can i throw db error at somewhere middle in the code

By Bheema

Thanks for your Ans But the thing i don't wants to change my SQL query. Because for extent it should work and then it should throw db error. So how should i throw db error intentionally

By Bheema

If you don't want to change your SQL then you will have to create a problem at the database end by ensuring some of your SQL fails - e.g., manually create a row which will cause a constraint to fail in your SQL, delete a key, change permissions etc. The possibilities are endless so I'm not listing all I can think of here.