Function update 

pub fn update(
    entity: &ResolvedEntity,
    id: &Value,
    body: &HashMap<String, Value>,
    schema_override: Option<&str>,
    caller_user_id: Option<&str>,
    dialect: &dyn Dialect,
) -> QueryBuf

UPDATE by id: SET only columns present in body (and in entity columns). Uses SQL cast for timestamp columns so string values bind correctly.