Exception classes

Exception classes define the kind of issues that can occur at runtime.

During a program execution, the following kind of issues may happen:

  1. Language errors : In case of invalid use of language instructions or API. For example, when specifying an unexisting form with the OPEN FORM instruction, or when opening an unexisting file with base.Channel.openFile().

  2. Expression errors : When an expression evaluation produces an error. For example, when a character string cannot be converted to a number type.

  3. SQL errors : If an SQL statement execution or SQL instruction returns an error. For example, when an INSERT statement violates a UNIQUE table constraint, or when doing a FETCH on an unopened cursor.

  4. SQL not found : When an SQL statement returns no data row(s). For example, when a FETCH statement reaches the end of the SQL cursor result set.

  5. SQL Warnings : If an SQL statement produces warning(s). For example, when fetching a character string value that gets truncated because the target VARCHAR variable is not long enough.

The default action can be changed by specifying the exception class in the WHENEVER instruction.

The following exception classes exist:
ERROR or SQLERROR
Triggered by a Language error or SQL error. Default exception action is STOP. The WHENEVER [SQL]ERROR and WHENEVER ANY [SQL]ERROR directives are mutually exclusive.
ANY ERROR or ANY SQLERROR
Triggered by a Language error, SQL error or Expression error. The WHENEVER ANY [SQL]ERROR and WHENEVER [SQL]ERROR directives are mutually exclusive. WHENEVER ANY ERROR has no default action, because the default is WHENEVER ERROR STOP, where Expression errors do not stop the program execution.
NOT FOUND
Triggered by SQL statements returning status NOTFOUND. Default exception action is CONTINUE. The action for WHENEVER NOT FOUND directive can be specified independently from other exception classes.
WARNING
SQL statements setting sqlca.sqlawarn flags. Default exception action is CONTINUE. The action for WHENEVER WARNING directive can be specified independently from other exception classes.
In the following code example, the WHENEVER instruction defines the behavior for the ANY ERROR exception class:
WHENEVER ANY ERROR CONTINUE