The Firebird 5.0 Language Reference

This section describes how to create, modify and delete custom exceptions for use in error handlers in PSQL modules.

`CREATE EXCEPTION`

Creates a custom exception for use in PSQL modules

Available in

DSQL, ESQL

Syntax

CREATE EXCEPTION exception_name '<message>'

<message> ::= <message-part> [<message-part> ...]

<message-part> ::=
    <text>
  | @<slot>

<slot> ::= one of 1..9

Table 1. `CREATE EXCEPTION` Statement Parameters
Parameter	Description
exception_name	Exception name.The maximum length is 63 characters
message	Default error message.The maximum length is 1,021 characters
text	Text of any character
slot	Slot number of a parameter.Numbering starts at 1.Maximum slot number is 9.

The statement CREATE EXCEPTION creates a new exception for use in PSQL modules.If an exception with the same name exists, the statement will raise an error.

The exception name is an identifier, see Identifiers for more information.

The default message is stored in character set NONE, i.e. in characters of any single-byte character set.The text can be overridden in the PSQL code when the exception is thrown.

The error message may contain “parameter slots” that can be filled when raising the exception.

Warning

If the message contains a parameter slot number that is greater than 9, the second and subsequent digits will be treated as literal text.For example @10 will be interpreted as slot 1 followed by a literal ‘0’.

Note	Custom exceptions are stored in the system table `RDB$EXCEPTIONS`.

Who Can Create an Exception

The CREATE EXCEPTION statement can be executed by:

Administrators
Users with the CREATE EXCEPTION privilege

The user executing the CREATE EXCEPTION statement becomes the owner of the exception.

`CREATE EXCEPTION` Examples

Creating an exception named E_LARGE_VALUE

CREATE EXCEPTION E_LARGE_VALUE
  'The value is out of range';

Creating a parameterized exception E_INVALID_VALUE

CREATE EXCEPTION E_INVALID_VALUE
  'Invalid value @1 for field @2';

EXCEPTION

EXCEPTION

CREATE EXCEPTION

Who Can Create an Exception

CREATE EXCEPTION Examples

`EXCEPTION`

`CREATE EXCEPTION`

`CREATE EXCEPTION` Examples