Comment by hn_throwaway_99
6 years ago
Actually, I think it's doubtful the folks at the private processing facility are actually writing 'NULL', but my guess is the DB field is just not set (i.e. left as NULL), and then when the info is read out somewhere it's just printed as the string literal value.
I'd guess that there is a CSV step involved.
Wouldn't their license plate be in quotes, though? 'NULL' != NULL
As my other comment points out, this is probably systems talking to systems talking to systems talking to systems to the nth degree. So even if the first system did in fact distinguish the NULL case from the string case, it only takes one system in the chain to be incapable of representing the difference to permanently and unrecoverably wreck it for all downstream systems.
What are the odds at least one system silently filters out apostrophes as invalid characters in license plate fields? Pretty good. These systems are often unattended, unmonitored processes often maintained by people who either can't fix errors upstream, or don't even want to, so these conversions are often written extremely permissively, trying to get through the data with whatever heuristics are necessary for the process to just Keep Working.
That makes perfect sense, and seems like those most likely explanation. Thanks.