chris.bland@... wrote:

> Hi there,
>
> We are using external files. We have varchar data with nulls in FB. When exporting this data to an external file, upon hex examination, a null value appears to be a series of NUL characters. When this is reimported, or selected, FB seems to interpret these as empty strings. The "null" has disappeared, and we now have empty strings. Is this correct behaviour, or are we doing something wrong? Is there a way to encode nulls?

External tables have a lot problems with NULL values.
You can try the tool I created just because of that. It may help you:

http://fbexport.sourceforge.net

If you know C++, feel free to modify the code to fit your needs.

--
Milan Babuskov
http://fbexport.sourceforge.net