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CDaoErrorInfo Structure

The CDaoErrorInfo structure contains information about an error object defined for data access objects (DAO).

struct CDaoErrorInfo 
{ 
   long m_lErrorCode; 
   CString m_strSource; 
   CString m_strDescription; 
   CString m_strHelpFile; 
   long m_lHelpContext; 
};

Parameters

  • m_lErrorCode
    A numeric DAO error code. See the topic "Trappable Data Access Errors" in DAO Help.

  • m_strSource
    The name of the object or application that originally generated the error. The Source property specifies a string expression representing the object that originally generated the error; the expression is usually the object's class name. For details, see the topic "Source Property" in DAO Help.

  • m_strDescription
    A descriptive string associated with an error. For details, see the topic "Description Property" in DAO Help.

  • m_strHelpFile
    A fully qualified path to a Microsoft Windows Help file. For details, see the topic "HelpContext, HelpFile Properties" in DAO Help.

  • m_lHelpContext
    A context ID for a topic in a Microsoft Windows Help file. For details, see the topic "HelpContext, HelpFile Properties" in DAO Help.

Remarks

MFC does not encapsulate DAO error objects in a class. Instead, the CDaoException class supplies an interface for accessing the Errors collection contained in the DAO DBEngine object, the object that also contains all workspaces. When an MFC DAO operation throws a CDaoException object that you catch, MFC fills a CDaoErrorInfo structure and stores it in the exception object's m_pErrorInfo member. (If you choose to call DAO directly, you must call the exception object's GetErrorInfo member function yourself to fill m_pErrorInfo.)

For more information about handling DAO errors, see the article Exceptions: Database Exceptions. For related information, see the topic "Error Object" in DAO Help.

Information retrieved by the CDaoException::GetErrorInfo member function is stored in a CDaoErrorInfo structure. Examine the m_pErrorInfo data member from a CDaoException object that you catch in an exception handler, or call GetErrorInfo from a CDaoException object that you create explicitly in order to check errors that might have occurred during a direct call to the DAO interfaces. CDaoErrorInfo also defines a Dump member function in debug builds. You can use Dump to dump the contents of a CDaoErrorInfo object.

Requirements

Header: afxdao.h

See Also

Reference

CDaoException Class

Other Resources

Structures, Styles, Callbacks, and Message Maps