Life isn't easy if your last name is 'Null' as it still breaks database entries the world over

[scrollone@feddit.it]

It's funny because I also learned on [Object object].

[notmyoldredditname@lemmy.world]

Hey AI can you swap this 2015 corolla with a green 2019 Mazda 2.

Keep the license plate the same!

And remember THERE ARE FOUR PASSENGER DOORS NOT 6

[llewellyn@lemm.ee]

What is a data beach?

[llewellyn@lemm.ee]

Sounds like a promise of magic!

[kava@lemmy.world]

How do devs make this mistake

it can happen many different ways if you're not explicitly watching out for these types of things

example let's say you have a csv file with a bunch of names

id, last_name
1, schaffer
2, thornton
3, NULL
4, smith
5, "NULL"

if you use the following to import into postgres

COPY user_data (id, last_name)
FROM '/path/to/data.csv'
WITH (FORMAT csv, HEADER true);

number 5 will be imported as a string "NULL" but number 3 will be imported as a NULL value. of course, this is why you sanitize the data but I can imagine this happening countless times at companies all over the country

there are easy fixes if you're paying attention

COPY user_data (id, last_name)
FROM '/path/to/data.csv'
WITH (FORMAT csv, HEADER true, NULL '');

sets the empty string to NULL value.

---

example with js

fetch('/api/user/1')
  .then(response => response.json())
  .then(data => {
    if (data.lastName == "null") {
      console.log("No last name found");
    } else {
      console.log("Last name is:", data.lastName);
    }
  });

if data is

data = {
  id: 5,
  lastName: "null"
};

then the if statement will trigger- as if there was no last name. that's why you gotta know the language you're using and the potential pitfalls

now you may ask -- why not just do

if (data.lastName === null)

instead? But what if the system you're working on uses JSON.parse(data) and that auto-converts everything to a string? it's a very natural move to check for the string "null"

obviously if you're paying attention and understand the pitfalls of certain languages (like javascript's type coercion and the particularities of JSON.parse()) it becomes easy but it's something that is honestly very easy to overlook

[cocodapuf@lemmy.world]

Thanks, I missed that

[sugar_in_your_tea@sh.itjust.works]

The most common source of security vulnerabilities is memory corruption and off by one errors.

[sugar_in_your_tea@sh.itjust.works]

And here I am at undefined years old, learning for the first time.

[sugar_in_your_tea@sh.itjust.works]

As a backbend dev, I blame DBAs. We were forced to support CSV imports from out support team so they could fix data issues on their own, and now we have some wonky data in prod...

[sugar_in_your_tea@sh.itjust.works]

Yup, then it becomes a front-end problem to deal with wonky input. As a backend dev, this is ideal, just give me data and I'll store it for ya.

[sugar_in_your_tea@sh.itjust.works]

Only noobs get hit by this (called SQL injection). That's why we have leads review code...

[sugar_in_your_tea@sh.itjust.works]

Two likely reasons:

• CSV got involved somewhere
• JavaScript

[undefined@lemmy.hogru.ch]

Lately I’ve been dealing with tons of invalid byte sequences in MySQL dumps and it makes me question what the hell they’re allowing in there.

[undefined@lemmy.hogru.ch]

Is it though? I haven’t used a framework since probably 2007 that doesn’t do this. There are the smaller, more DIY frameworks out there but I’ve never used them professionally.

[undefined@lemmy.hogru.ch]

Yeah that’s a whole other can of worms. I see this a lot at work where people are asking for direct database credentials and cringe every time.

[and009@lemmynsfw.com]

I'm a year old undefined and I find it [redacted]

[chewbaccabra@lemmy.world]

Like you said, GIGO, but I can't say I'm familiar with any csv looking like that. Maybe I'm living a lucky life, but true null would generally be an empty string, which of course would still be less than ideal. From a general csv perspective, NULL without quotes is still a string.

If "NULL" string, then lord help us, but I would be inclined to handle it as defined unless instructed otherwise. I guess it's up to the dev to point it out and not everyone cares enough to do so. My point is these things should be caught early.

I'll admit I'm much more versed in mysql than postgres.

[__nobodynowhere@sh.itjust.works]

That boy ain't right

[mysticpickle@lemmy.ca]

Mandatory xkcd:

[kogasa@programming.dev]

Code is easy in a vacuum. 50 moving parts all with their own quirks and insufficient testing is how you get stuff like this to happen.