How to store a 128 bit integer with nHibernate?

Question

Question:

How can I store a 128 bit integer (IPv6) with nHibernate ?

Especially on Firebird, where the BigInteger MAX size is 2^64 .

I want to do calculations like :

SELECT * FROM T_Country_IP_Range 
WHERE 
(block_from <= @in_IP) 
AND (block_to >= @in_ip)

So storing it as text/varchar/char is not an option.

Answer 1

It seems indeed that there is no firebird support for INT128.

What you can do is represent the 128bits as two 64 bit fields, the upper 64bit in one field (IP_upper) and the lower 64bits in the other (IP_Lower).

All comparison operation will have to compare both fields. If the upper field is smaller/larger or if it's equal and then check the lower field:

SELECT * FROM T_Country_IP_Range 
WHERE 
(
    block_from_upper < @in_IP_upper 
    OR 
    (block_from_upper = @in_IP_upper AND block_from_lower <= @in_IP_lower)
) 
AND 
(
    block_to_upper > @in_IP_upper 
    OR 
    (block_to_upper = @in_IP_upper AND block_to_lower >= @in_IP_lower)
)

Kinda awkward, no doubt