APEX

We are at the end of completing a project and we ran into a last minute bug. We are using two primary keys on a table to form a unique key. The problem we have is the program hangs up and gives us the following error,

ORA-20001: Error in DML: p_rowid=CUA, p_alt_rowid=SIT_ID, p_rowid2=, p_alt_rowid2=. ORA-01422: exact fetch returns more than requested number of rows,

probably meaning we only have one key setup in the DML
processing when our table has two.
we created a process with the Primary key set up in the DML but how does the secondary key column value work and is that what it's used for,because we tryed with no success. Is there a way around this problem without having to change our table by inserting only one primary key.

Thanks in advance.

Garry