OpenDBX::Exception Class Reference

Exceptions thrown by the OpenDBX classes. More...

List of all members.

Public Member Functions
	Exception (const string &msg, int err, int type) throw ()
	Initializes the exception object.
int	getCode () const throw ()
	Returns the OpenDBX error code related to the error.
int	getType () const throw ()
	Returns severity indicator.

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Detailed Description

Exceptions thrown by the OpenDBX classes.

Most calls to methods of OpenDBX objects does throw an exception in case an error occurs in the underlying database library. Additionally to other exceptions which inherit from the STL exception class it will not only contain a translated error message depending on the user settings but also a machine readable error code and an indicator for the severity of the eror.

Author:

Norbert Sendetzky <norbert@linuxnetworks.de>

Version:

1.0

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Constructor & Destructor Documentation

OpenDBX::Exception::Exception	(	const string &	msg,
		int	err,
		int	type
	)		throw ()

Initializes the exception object.

The first parameter, the error message, should be the human readable description of what has gone wrong. It should also be already translated to the language of the user which depends on his environment settings when e.g GNU gettext is used. Errors thrown by the OpenDBX C++ library are already translated.

The OpenDBX error code is the machine readable code for the error which has been occured.

The last parameter must be a value indicating the severity of the thrown error. If the value is smaller than zero, the error is fatal and the connection to the database can't be recovered and has to be closed and reopened before the application can try to continue. In case it's greater than zero, the operation failed but the database connection is still usable. Zero represents a successful operation and shouldn't be used because an exception should only be thrown in error conditions.

Parameters:

msg	Human readable error message
err	OpenDBX error code
type	Severity of error (negative: fatal, zero: success, positive: warning)

Returns:

Exception

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Member Function Documentation

int OpenDBX::Exception::getCode

(

)

const throw ()

Returns the OpenDBX error code related to the error.

The machine readable code describing the error which occured can be used by the application to act differently depending on the specific error. Currently defined codes are:

• ODBX_ERR_SUCCESS
  The operation was successfully completed.
• ODBX_ERR_BACKEND
  An error occured in the native database library or in the database server.
• ODBX_ERR_NOCAP
  The capability isn't available in the currently selected backend.
• ODBX_ERR_PARAM
  One of the given parameters is invalid and doesn't match the expectations.
• ODBX_ERR_NOMEM
  An out of memory condition occured.
• ODBX_ERR_SIZE
  The internally allocated memory is unable to store the value.
• ODBX_ERR_NOTEXIST
  The backend library wasn't found or loading the library failed.
• ODBX_ERR_NOOP
  The required function isn't available or the operation isn't possible in this backend.
• ODBX_ERR_OPTION
  The given option is unknown an therefore invalid.
• ODBX_ERR_OPTRO
  The requested option is read-only and its value can't be changed.
• ODBX_ERR_OPTWR
  Setting the given option to the new value failed.
• ODBX_ERR_RESULT
  Waiting for the result set after sending a statement to the database server failed.
• ODBX_ERR_NOTSUP
  The requested functionality isn't supported by the backend.
• ODBX_ERR_HANDLE
  The internal data structure which should store the details for accessing the database are invalid.

Returns:

Error code

int OpenDBX::Exception::getType

(

)

const throw ()

Returns severity indicator.

The returned value classifies the error thrown. In case it is negative, the error is fatal (e.g. the connection to the database is lost) and the application can't continue without closing and reopening the connection.

If the value is positive, the database wasn't able to perform the requested action but the connection is still OK and can be used to send more requests to the database. On zero, everything was successfull and no error occured. This shouldn't happen when catching one of these exceptions.

Returns:

Severity of error (negative: fatal, zero: success, positive: warning)

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The documentation for this class was generated from the following file:

• opendbx/api