A type with its domains looked through. tokio-postgres resolves a
domain’s typbasetype once per connection, and a domain’s base type
never changes, so the cached Kind::Domain is always current.
Refuse, before a statement runs, result columns the v2 envelope cannot
carry: a type it does not render, or a name that appears twice (a row is
keyed by column name).
Convert a single Postgres column into a serde_json::Value, mapping common
scalar types faithfully. Unknown types fall back to the column’s text
representation. Used by both the SQL query endpoint (streaming rows to the
CLI) and the WASM runtime’s host DB bridge.
A column’s value in the db_call v2 row envelope: every supported type
rendered exactly, and an error naming the column rather than a silent
null for anything else.