insert_all

insert_all(&self, values: Vec<T>) where T derives #[derive(SqlxInsert)] (see insert) — a single multi-row INSERT for the whole batch, one round-trip.

async fn insert_all(&self, values: Vec<UserValues>) -> sqlx::Result<Vec<UserRow>>;

Void vs. row-returning works the same as insert — declare -> sqlx::Result<()> to skip fetching the written rows back. An empty Vec short-circuits to Ok(vec![]) / Ok(()) without touching the database.

Per-dialect SQL

Postgres/SQLite: built with sqlx::QueryBuilder::push_values — INSERT INTO "table" (cols...) VALUES ($1,$2),($3,$4),... RETURNING *.

MySQL has no RETURNING. The row-returning form does the batch INSERT, then re-SELECTs by primary-key range: SELECT * WHERE {key} >= first_id AND {key} < first_id + rows.len() ORDER BY {key}, relying on MySQL's contiguous auto-increment allocation for a single multi-row insert statement (true under the default innodb_autoinc_lock_mode). If the table's {key} isn't an auto-increment column, this will not return the right rows — use the ()-returning form or a method body instead in that case.