Common Oracle error codes.

ORA-00001 Unique constraint violated. (Invalid data has been rejected)

ORA-00600 Internal error (contact support)

ORA-03113 End-of-file on communication channel (Network connection lost)

ORA-03114 Not connected to ORACLE 

ORA-00942 Table or view does not exist 

ORA-01017 Invalid Username/Password

ORA-01031 Insufficient privileges 

ORA-01034 Oracle not available (the database is down)

ORA-01403 No data found

ORA-01555 Snapshot too old (Rollback has been overwritten)


ORA-12154 TNS:could not resolve service name
ORA-12203 TNS:unable to connect to destination
ORA-12500 TNS:listener failed to start a dedicated server process
ORA-12545 TNS:name lookup failure
ORA-12560 TNS:protocol adapter error
ORA-02330 Package error raised with DBMS_SYS_ERROR.RAISE_SYSTEM_ERROR

Other error prefix codes

PLS-????? PL/SQL Error
IMP-????? Import error
EXP-????? Export error
MOD-????? SQL Module error
FRM-????? Oracle Forms error
SQL-Loader-??? SQL Loader error

Source: ss64.com