Oracle PL/SQL Language Pocket Reference, 4th Edition

Exception Handling

PL/SQL allows developers to raise and handle errors (exceptions) in a very flexible and powerful way. Each PL/SQL block can have its own exception section in which exceptions can be trapped and handled (resolved or passed on to the enclosing block). When an exception occurs (is raised) in a PL/SQL block, its execution section immediately terminates. Control is passed to the exception section. Every exception in PL/SQL has an error number and error message; some exceptions also have names.

Declaring Exceptions

Some exceptions have been predefined by Oracle in the STANDARD package or other built-in packages, such as UTL_FILE. See the following table for some of the most common predefined exceptions. You also can declare your own exceptions as follows:

DECLARE
   exception_name EXCEPTION;

Error	Named exception
ORA-00001	DUP_VAL_ON_INDEX
ORA-00051	TIMEOUT_ON_RESOURCE
ORA-00061	TRANSACTION_BACKED_ OUT
ORA-01001	INVALID_CURSOR
ORA-01012	NOT_LOGGED_ON
ORA-01017	LOGIN_DENIED
ORA-01403	NO_DATA_FOUND
ORA-01410	SYS_INVALID_ROWID
ORA-01422	TOO_MANY_ROWS
ORA-01476	ZERO_DIVIDE
ORA-01725	USERENV_COMMMITSCN_ ERROR
ORA-01722	INVALID_NUMBER
ORA-06500	STORAGE_ERROR
ORA-06501	PROGRAM_ERROR
ORA-06502	VALUE_ERROR
ORA-06504	ROWTYPE_MISMATCH
ORA-06511	CURSOR_ALREADY_OPEN
ORA-06530	ACCESS_INTO_NULL
ORA-06531	COLLECTION_IS_NULL
ORA-06532	SUBSCRIPT_OUTSIDE_LIMIT
ORA-06533	SUBSCRIPT_BEYOND_COUNT
ORA-06548	NO_DATA_NEEDED
ORA-06592	CASE_NOT_FOUND
ORA-30625	SELF_IS_NULL

An exception can be declared only once in a block, but nested blocks can declare ...