Function json_object_agg 

pub fn json_object_agg<'a, V, K, Val>(
    key: K,
    value: Val,
) -> SQLExpr<'a, V, <V::DialectMarker as DialectTypes>::Json, Null, Agg>
where
    V: SQLParam + 'a,
    V::DialectMarker: PostgresAggregateSupport,
    K: Expr<'a, V>,
    Val: Expr<'a, V>,

JSON_OBJECT_AGG - aggregates key/value pairs into a JSON object (PostgreSQL).

Example

use drizzle_core::expr::json_object_agg;

// SELECT JSON_OBJECT_AGG(settings.key, settings.value)
let obj = json_object_agg(settings.key, settings.value);