By default, any error occurring in an SPL program aborts execution of the program. You can trap errors and recover from them by using a BEGIN block that has an EXCEPTION section. The corresponding syntax is an extension of the normal syntax for a BEGIN block:
[ DECLARE declarations ] BEGIN statements EXCEPTION WHEN condition [ OR condition ]... THEN handler_statements [ WHEN condition [ OR condition ]... THEN handler_statements ]... END;
If no error occurs, this form of block simply executes all the statements, and then control passes to the next statement after END. If an error occurs within the statements, further processing of the statements is abandoned, and control passes to the EXCEPTION list. The list is searched for the first condition matching the error that occurred. If a match is found, the corresponding handler_statements are executed, and then control passes to the next statement after END. If no match is found, the error propagates out as though the EXCEPTION clause did not exist. The error can be caught by an enclosing block with EXCEPTION. If no enclosing block exists, the error aborts processing of the subprogram.
The special condition name OTHERS matches every error type. Condition names are not case-sensitive.
If a new error occurs within the selected handler_statements, the error cannot be caught by this EXCEPTION clause, but is propagated out. A surrounding EXCEPTION clause can catch the error.
The following table lists the condition names that may be used.
|CASE_NOT_FOUND||The application has encountered a situation where none of the cases in a CASE statement evaluates to TRUE and no ELSE condition exists.|
|COLLECTION_IS_NULL||The application has attempted to invoke a collection method on a null collection such as an uninitialized nested table.|
|CURSOR_ALREADY_OPEN||The application has attempted to open a cursor that is already open.|
|DUP_VAL_ON_INDEX||The application has attempted to store a duplicate value that currently exists within a constrained column.|
|INVALID_CURSOR||The application has attempted to access an unopened cursor.|
|INVALID_NUMBER||The application has encountered a data exception (equivalent to SQLSTATE class code 22). INVALID_NUMBER is an alias for VALUE_ERROR.|
|NO_DATA_FOUND||No rows satisfy the selection criteria.|
|OTHERS||The application has encountered an exception that has not been caught by a prior condition in the exception section.|
|SUBSCRIPT_BEYOND_COUNT||The application has attempted to reference a subscript of a nested table or varray beyond its initialized or extended size.|
|SUBSCRIPT_OUTSIDE_LIMIT||The application has attempted to reference a subscript or extend a varray beyond its maximum size limit.|
|TOO_MANY_ROWS||The application has encountered more than one row that satisfies the selection criteria (where only one row is allowed to be returned).|
|VALUE_ERROR||The application has encountered a data exception (equivalent to SQLSTATE class code 22). VALUE_ERROR is an alias for INVALID_NUMBER.|
|ZERO_DIVIDE||The application has tried to divide by zero.|
|User-defined Exception||For more information, see User-defined exceptions.|