The following table lists circumstances under which a connection might fail and describes the responses you might receive.

Table 1. Failure responses
Failure circumstances Results
During startup The system displays an error message and returns to the operating system prompt.
During a CONNECT statement The system aborts the remainder of the CONNECT statement (as though the remainder never existed) and a run-time error condition occurs. Any connections you made previous to the failed connection remain in effect. You can use the NO-ERROR modifier with the CONNECT statement to trap run-time errors. If you use the NO-ERROR modifier and it fails, you see the same failure behavior as you do with an unsuccessful CONNECT statement. However, run-time error conditions do not occur.
During an attempted auto-connect The system aborts the remainder of the connect (as though the remainder never existed) and a run-time error condition occurs. Any connections you made previous to the failed connection remain in effect. There is no way to trap auto-connect run-time error conditions.
During an attempt to connect using the Data Dictionary The Data Dictionary displays an error message and returns to the main window.
During an attempt to connect a connected database with a different logical name The system responds with a run-time error condition and you can continue. You can use the NO-ERROR modifier to suppress the error.
During an attempt to connect a connected database with the same logical name The system responds with a warning and you can continue. You can use the NO-ERROR option to suppress the warning.
During an attempt to connect an unconnected database, when the logical name is already in use by a connected database The system responds with a run-time error condition and you cannot connect to the second database.
During an attempt to connect to an Oracle database that uses a double-byte character set The system responds with an error that the code page of the database and the -cpinternal value differ. You also receive messages about missing conversion tables.