Guest-side database access over the db.* host calls (abiv1 db.proto),
two surfaces sharing one injected transport:
- database/sql driver registered as "bnwasm" (driver.go) — QueryContext/
ExecContext/BeginTx over db.query/db.exec/db.tx_*; named args rejected.
- plugin.Pool (pool.go) handing out a pgx.Tx-shaped value (tx.go), so the
pgx-flavored sqlc DBTX every current plugin generates against
(sql_package: pgx/v5) is satisfied with no source edits. This is the
primary path: their DBTX needs pgconn.CommandTag/pgx.Rows/pgx.Row, which
database/sql cannot produce.
DbValue↔Go mapping (dbvalue.go) covers all 11 oneof arms both directions;
DbError surfaces as *pgconn.PgError (SQLSTATE preserved for errors.As);
nested tx/savepoints rejected with a clear error (no fleet plugin uses
them). The scan contract is pinned in the exported DbValueFixtures table
(dbvalue_fixtures.go) that the WO-WZ-007 host executor mirrors.
Tests: driver_test.go (fake host — every DbValue variant round-trips with
correct scan types, exec rows-affected, ordered host-call assertions for
tx commit/rollback sequences, post-rollback autocommit carries no handle)
and sqlcgen_test.go (vendored sqlc-style Queries + WithTx run against the
fake host). Native + wasip1 builds green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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