Subject Re: NULL vs. Empty String
Author Adam
--- In, Yoel Polsky <polsky@...> wrote:
> Hi,
> I'm importing data from Excel into Firebird 2.0 as text. All of the
> contain some empty cells. I was wondering if it is better to import
> as NULL values or to leave them as empty strings? What are the future
> ramifications - is it just a matter of how the queries will be written,
> or are their other factors to take into consideration?

Hello Yoel,

There is a difference in definition between null and ''. Before making
your decision, download the 'Firebird Null Guide' from here:

In a nutshell, use empty when you know the value, and the value is ''.
Use null when you don't know the value. There are certainly
implications with respect to comparisons, uniqueness and
concatenations just to name a few. You also need to be aware that some
older UDF libraries may not handle null well.

So it is really important you understand your data and use the right
tool for the right job.