bug report | null primary keys fail to sync

[tantaman]

example of the error: https://discord.com/channels/989870439897653248/1022913265946349690/1152224235461287977

reported by @jmatsushita

[tantaman]

Null primary keys violate unique constraints --

We can't support a null primary key and no DB actually does besides SQLite. To add validation on crr creation to deny making crrs that have null primary keys.

[Azarattum]

So, crsqlite now has to require NOT NULL on primary key definition, right? What about tables with multiple primary keys? Is it ok if only one of pk columns is nullable?

[Azarattum]

Oh. The original report was because of the composite keys... All the pk columns should be NOT NULL then.

[tantaman]

Yeah, I think all columns need to be not null.

Even allowing a single primary key column to be null gives bogus behavior:

sqlite> create table baz (a integer not null, b integer, primary key(a, b));
sqlite> insert into baz values (1, null);
sqlite> insert into baz values (1, null);
sqlite> insert into baz values (1, null);
sqlite> insert into baz values (1, 1);
sqlite> insert into baz values (1, 1);
Runtime error: UNIQUE constraint failed: baz.a, baz.b (19)
sqlite> select * from baz;
┌───┬──────┐
│ a │  b   │
├───┼──────┤
│ 1 │ NULL │
│ 1 │ NULL │
│ 1 │ NULL │
│ 1 │ 1    │
└───┴──────┘
sqlite>