I complain that mainstream SQL engines have no problem returning less than the total number of rows if you first query WHERE column = NULL and then query WHERE column <> NULL. Your example queries remind me of that.
[1] https://medium.com/dailyjs/the-why-behind-the-wat-an-explana...
> WHERE column = NULL and then query WHERE column <> NULL
NULL means what it means and is conceptually foundational to SQL. Comparing it to anything returns UNKNOWN, the “third value” besides true and false. And WHERE needs a TRUE predicate. So your implied fault that they “have no problem“ really is just a matter of you not understanding the tool you are complaining about.
To match against the NULLness of a value you must use special purpose operators. In this case
WHERE column IS NULL OR column IS NOT NULL You could write predicates over non-existent columns:
root=> SELECT * FROM t
WHERE definitely_not_a_column = 4;
SELECT * FROM t WHERE 4 = 5;
a | b
---+----
5 | 6
(1 row)
System.out.println(((Integer)4).compareTo((Integer)5));
> -1
So it's SELECT FROM t WHERE true;
Now, let's get busy blaming Jepsen for using the tool wrong.
No, therefore the condition is unsatisfiable and equivalent to WHERE FALSE. And that's letting you ignore the SQL spec, which says the query is invalid and should return "Column not found" because the column name cannot be resolved.
> We're comparing 4 and 5. Precedent?
I really hope you're trolling, for your own sake.
The condition is unsatisfiable, and the engine went ahead and gave a 0-warning result?
1) It would be no more fucked up than anything else that has been grandfathered into our tools.
2) If it already had mass adoption in the market, people would jump onto this thread to explain to me that I just don't understand the brilliant semantics behind language of why 4 = 5.
Brilliant semantics? No one said anything normative. You’re arguing with yourself on your own non-sequitur. SQL is SQL. It’s extremely flawed but who freaking cares, that’s why ParticleDB shouldn’t have tried to implement SQL let alone full postgres compatibility when they clearly are not equipped to do so! Your comments about how strange and non-intuitive SQL are true but irrelevant.
No. No-one would ever accept a database with _this_ level of brokenness. Like, this makes early Mongo and noughties-era mysql look _amazing_.
> I complain that mainstream SQL engines have no problem returning less than the total number of rows if you first query WHERE column = NULL and then query WHERE column <> NULL.
You may not like it, but that is entirely deliberate and internally consistent. Blame the people who came up with SQL in the 70s; far too late to change it now.
That's why I preplied:
> if enough people did it that way it would be the new normal, and apologists would fall out of the woodwork
If 4=5 made it into the spec, would it be no longer up for criticism?