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Object reference not set to an instance of an object.S

barry parish
over 5 years ago

Using "Export / Export Wizard" so that I can get SQL statement included in results.  Right-clicking in results to initiate export. 

Works fine with statement with no parameter.  But with statement with a parameter, such as "Select part_nbr from parts_db where part_nbr = &myPart" I get the error below when attempting to export the results using the Export Wizard.  Is there any way in Toad Data Point to export the results with the SQL when the SQL contains a variable/parameter???

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  • 0 over 3 years ago

    An Object is an instance of a Class , it is stored some where in memory. A reference is what is used to describe the pointer to the memory location where the Object resides. The message "object reference not set to an instance of an object" means that you are referring to an object the does not exist or was deleted or cleaned up. It's usually better to avoid a NullReferenceException than to handle it after it occurs. To prevent the error, objects that could be null should be tested for null before being used.

    if (mClass != null)
    {
    // Go ahead and use mClass
    mClass.property = ...
    }
    else
    {
    // Attempting to use mClass here will result in NullReferenceException
    }

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  • 0 over 3 years ago

    An Object is an instance of a Class , it is stored some where in memory. A reference is what is used to describe the pointer to the memory location where the Object resides. The message "object reference not set to an instance of an object" means that you are referring to an object the does not exist or was deleted or cleaned up. It's usually better to avoid a NullReferenceException than to handle it after it occurs. To prevent the error, objects that could be null should be tested for null before being used.

    if (mClass != null)
    {
    // Go ahead and use mClass
    mClass.property = ...
    }
    else
    {
    // Attempting to use mClass here will result in NullReferenceException
    }

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