issue_comments

I think the key feature I need here is going to be the equivalent of ignore=True and replace=True for dealing with primary key collisions, see https://sqlite-utils.datasette.io/en/stable/reference.html#sqlite_utils.db.Table.insert

So maybe they're not actually worth worrying about separately, because they are guaranteed to have a primary key set.

One last case to consider: WITHOUT ROWID tables.

https://www.sqlite.org/withoutrowid.html

By default, every row in SQLite has a special column, usually called the "rowid", that uniquely identifies that row within the table. However if the phrase "WITHOUT ROWID" is added to the end of a CREATE TABLE statement, then the special "rowid" column is omitted. There are sometimes space and performance advantages to omitting the rowid.

...

Every WITHOUT ROWID table must have a PRIMARY KEY. An error is raised if a CREATE TABLE statement with the WITHOUT ROWID clause lacks a PRIMARY KEY.

Actually, for simplicity I'm going to say that you can always set the primary key, even for auto-incrementing primary key columns... but you cannot set it on pure rowid columns.

Some notes on what Datasette does already

https://latest.datasette.io/fixtures/tags.json?_shape=array returns: json [ { "tag": "canine" }, { "tag": "feline" } ] That table is defined like this: sql CREATE TABLE tags ( tag TEXT PRIMARY KEY ); Here's a rowid table with no explicit primary key: https://latest.datasette.io/fixtures/binary_data

https://latest.datasette.io/fixtures/binary_data.json?_shape=array json [ { "rowid": 1, "data": { "$base64": true, "encoded": "FRwCx60F/g==" } }, { "rowid": 2, "data": { "$base64": true, "encoded": "FRwDx60F/g==" } }, { "rowid": 3, "data": null } ] sql CREATE TABLE binary_data ( data BLOB ); https://latest.datasette.io/fixtures/simple_primary_key has a text primary key:

https://latest.datasette.io/fixtures/simple_primary_key.json?_shape=array json [ { "id": "1", "content": "hello" }, { "id": "2", "content": "world" }, { "id": "3", "content": "" }, { "id": "4", "content": "RENDER_CELL_DEMO" }, { "id": "5", "content": "RENDER_CELL_ASYNC" } ] sql CREATE TABLE simple_primary_key ( id varchar(30) primary key, content text ); https://latest.datasette.io/fixtures/compound_primary_key is a compound primary key.

https://latest.datasette.io/fixtures/compound_primary_key.json?_shape=array json [ { "pk1": "a", "pk2": "b", "content": "c" }, { "pk1": "a/b", "pk2": ".c-d", "content": "c" } ] sql CREATE TABLE compound_primary_key ( pk1 varchar(30), pk2 varchar(30), content text, PRIMARY KEY (pk1, pk2) );

I checked and SQLite itself does allow you to set the rowid on that kind of table - it then increments from whatever you inserted: % sqlite3 /tmp/t.db SQLite version 3.39.4 2022-09-07 20:51:41 Enter ".help" for usage hints. sqlite> create table docs (title text); sqlite> insert into docs (title) values ('one'); sqlite> select rowid, title from docs; 1|one sqlite> insert into docs (rowid, title) values (3, 'three'); sqlite> select rowid, title from docs; 1|one 3|three sqlite> insert into docs (title) values ('another'); sqlite> select rowid, title from docs; 1|one 3|three 4|another

If a table has an auto-incrementing primary key, should you be allowed to insert records with an explicit key into it?

I'm torn on this one. It's something you can do with direct database access, but it's something I very rarely want to do.

I'm inclined to disallow it and say that if you want that you can get it using a writable canned query instead.

Likewise, I'm not going to provide a way to set the rowid explicitly on a freshly inserted row.

Relevant TODO: https://github.com/simonw/datasette/blob/c35859ae3df163406f1a1895ccf9803e933b2d8e/datasette/views/table.py#L1131-L1135