SELECT di.index_id,
di.time_code,
di.time_type,
di.begin_time,
di.end_time,
di.data_time,
di.value,
di.quality,
di.create_time,
di.update_time,
ci.code AS "index_code",
ci.name AS "index_name"
FROM data_item di
LEFT JOIN energy_index ci ON di.index_id = ci.index_id