- An internal exception is raised implicitly whenever your PL/SQL program violates an Oracle rule or exceeds a system-dependent limit.
- Every Oracle error has a number, but exceptions must be handled by name.
- So, PL/SQL predefines some common Oracle errors as exceptions.
- For example, PL/SQL raises the predefined exception NO_DATA_FOUND if a SELECT INTO statement returns no rows.
- To handle other Oracle errors, the OTHERS handler can be used.
- The functions SQLCODE and SQLERRM are especially useful in the OTHERS handler because they return the Oracle error code and message text.
- Alternatively, you can use the pragma EXCEPTION_INIT to associate exception names with Oracle error codes.
- PL/SQL declares predefined exceptions globally in package STANDARD, which defines the PL/SQL environment. So, they need not be declared by themselves.
| ACCESS_INTO_NULL | The program attempts to assign values to the attributes of an uninitialized (automatically null) object. |
| CASE_NOT_FOUND | None of the choices in the WHEN clauses of a CASE statement is selected, and there is no ELSE clause. |
| COLLECTION_IS_NULL | The program attempts to apply collection methods other than EXISTS to an uninitialized (atomically null) nested table or varray, or the program attempts to assign values to the elements of an uninitialized nested table or varray. |
| CURSOR_ALREADY_OPEN | The program attempts to open an already open cursor. A cursor must be closed before it can be reopened. A cursor FOR loop automatically opens the cursor to which it refers. So, your program cannot open that cursor inside the loop. |
| DUP_VAL_ON_INDEX | The program attempts to store duplicate values in a database column that is constrained by a unique index. |
| INVALID_CURSOR | The program attempts an illegal cursor operation such as closing an unopened cursor. |
| INVALID_NUMBER | In a SQL statement, the conversion of a character string into a number fails because the string does not represent a valid number. (In procedural statements, VALUE_ERROR is raised.) This exception is also raised when the LIMIT-clause expression in a bulk FETCH statement does not evaluate to a positive number. |
| LOGIN_DENIED | The program attempts an illegal cursor operation such as closing an unopened cursor. |
| NO_DATA_FOUND | A SELECT INTO statement returns no rows, or your program references a deleted element in a nested table or an uninitialized element in an index-by table. SQL aggregate functions such as AVG and SUM always return a value or a null. So, a SELECT INTO statement that calls an aggregate function never raises NO_DATA_FOUND. The FETCH statement is expected to return no rows eventually, so when that happens, no exception is raised. |
| NOT_LOGGED_ON | The program issues a database call without being connected to Oracle. |
| PROGRAM_ERROR | PL/SQL has an internal problem. |
| ROWTYPE_MISMATCH | The host cursor variable and PL/SQL cursor variable involved in an assignment have incompatible return types. For example, when an open host cursor variable is passed to a stored subprogram, the return types of the actual and formal parameters must be compatible. |
| SELF_IS_NULL | The program attempts to call a MEMBER method on a null instance. That is, the built-in parameter SELF (which is always the first parameter passed to a MEMBER method) is null. |
| STORAGE_ERROR | PL/SQL runs out of memory or memory has been corrupted. |
| SUBSCRIPT_BEYOND_COUNT | The program references a nested table or varray element using an index number larger than the number of elements in the collection. |
| SUBSCRIPT_OUTSIDE_LIMIT | The program references a nested table or varray element using an index number (-1 for example) that is outside the legal range. |
| SYS_INVALID_ROWID | The conversion of a character string into a universal rowid fails because the character string does not represent a valid rowid. |
| TIMEOUT_ON_RESOURCE | PA time-out occurs while Oracle is waiting for a resource. |
| TOO_MANY_ROWS | A SELECT INTO statement returns more than one row. |
| VALUE_ERROR | An arithmetic, conversion, truncation, or size-constraint error occurs. For example, when your program selects a column value into a character variable, if the value is longer than the declared length of the variable, PL/SQL aborts the assignment and raises VALUE_ERROR. In procedural statements, VALUE_ERROR is raised if the conversion of a character string into a number fails. (In SQL statements, INVALID_NUMBER is raised.) |
| ZERO_DIVIDE | The program attempts to divide a number by zero. |
