[m13m]

Every statement that returns no rows now works end to end against a real server — INSERT, UPDATE, DELETE, CREATE, DROP, SET, USE.

{:ok, insert, client} = Client.query(client, "INSERT INTO widgets (name) VALUES ('first')")
insert.affected_rows   # => 1
insert.last_insert_id  # => 1

58 tests with --include integration; 50 and 4 excluded without.

The command is trivial, the response is the work

COM_QUERY is one byte and the SQL, since CLIENT_QUERY_ATTRIBUTES is not claimed. Its response is decided entirely by the first byte:

0x00  OK      the statement returned no rows
0xFF  ERR     it failed
0xFB  LOCAL INFILE — the server wants a file from the client
else  a length-encoded column count, introducing a resultset

What to look at

0xFB is refused outright. CLIENT_LOCAL_FILES is not claimed, so a server asking the client to upload a file is either broken or hostile. The answer is an error, not a filesystem read. This is the attack the capability refusal in #5 was guarding against, and here is where that guard actually pays.

A resultset returns :resultset_not_implemented rather than a guess, and the integration test asserts that against a real SELECT. The gap is visible in the suite rather than implied by its absence.

Sequence ids reset per command. The statement goes out as 0 and the reply arrives as 1. This is the tracking phase 1 deliberately deferred until there was a command to track it across — see the "deliberately not here" list in ROADMAP.md.

query/3 returns three-tuples — {:ok, result, client} / {:error, reason, client} — so the read buffer threads through. Leftover bytes from one message belong to the next, and the client is the only thing that can carry them.

Integration coverage

Against MySQL 8.0: creates a table, inserts two rows and checks both AUTO_INCREMENT ids, verifies Rows matched: 1 in an update's info string, and gets 1146 / 42S02 / "doesn't exist" back for a missing table.

Next

The resultset: column count, column definitions, then rows as length-encoded strings with 0xFB for NULL. Every codec it needs already exists, so it is three packet parsers and a loop.