The SQL dialect, used only to translate a nested JSON filter path (field: ['profile', 'city']). No two dialects spell JSON extraction alike: PostgreSQL uses #>>, MySQL JSON_UNQUOTE(JSON_EXTRACT(...)) and SQLite json_extract.

Absent, the adapter reads the dialect off the Drizzle instance, which covers every instance Drizzle ships. Set it when that detection cannot name the dialect — a nested-path filter is then refused by name rather than emitted in a guessed syntax that would return wrong rows.