database

Connect to PostgreSQL, MySQL, and SQLite from the iii engine. Run read-only queries, write statements, atomic transactions, and prepared-statement sequences over a managed per-database connection pool. Every callable surface lives under the single database::* namespace; SQLite is the recommended starting point because it needs no server, just a file.

The worker resolves the driver from each database's URL scheme (sqlite:, postgres://, postgresql://, mysql://). For the databases: config block, TLS modes, error-code reference, and the per-driver compatibility table (e.g. returning: is a no-op on MySQL; SQLite degrades read_committed / repeatable_read to serializable), see the README.

How-tos

database::*

• database::query — read-only SQL; returns { rows, row_count, columns } for SELECT-style statements.
• database::execute — write SQL (INSERT/UPDATE/DELETE/DDL); returns { affected_rows, last_insert_id, returned_rows }.
• database::prepareStatement + database::runStatement — prepare-once, run-many parameterized SQL; the prepare step pins a pool connection until TTL expiry, so always run before re-issuing the same statement many times.
• database::transaction — atomic batch sequence; one call, pass every statement together, rolls back on first failure with a failed_index pointer at the offending step.
• database::beginTransaction + transactionQuery / transactionExecute + commitTransaction / rollbackTransaction — stateful interactive transaction with a configurable timeout-driven auto-rollback. Use this when you need read-your-writes across several round-trips inside a single transaction.

database::row-change (Postgres logical replication via pgoutput) is registered as a trigger type but is not yet functional in v1.0.0: register_trigger returns UNSUPPORTED while the streaming decode loop waits on an upstream tokio-postgres replication API release. Operators can pre-provision slots and publications now; see the Triggers section of the README for current status and cleanup commands.