Mysql query enhancement for union - php

Question

I have this query that will be used for reports and i have a lot of data.
As of the moment is this my query that uses of UNION ALL over UNION because i remembered last project i used the UNION is that it dont unite all the datas and i never knew why so i used the UNION ALL
SELECT `item_id`, NULL AS `ob`,SUM(`add`) AS `add` ,NULL AS `dam`,NULL AS `sold`,NULL AS `others`,NULL AS `ac`
FROM (
-- DELIVERED ITEMS
SELECT si.`item_id`,SUM(sdi.`actual_pcs`) AS `add`
FROM `store_inventory` si
LEFT JOIN `store_delivery` sd
ON sd.`store_id` = si.`store_id` AND DATE(sd.`dt_modified`) = '2018-09-01'
AND sd.`status` = "DONE"
LEFT JOIN `store_delivery_items` sdi
ON sdi.`strd_id` = sd.`strd_id` AND sdi.`item_id` = si.`item_id`
WHERE si.`store_id` = '4'
GROUP BY si.`item_id`
UNION ALL
-- OVERRIDE ADD (ADD)
SELECT si.`item_id`,SUM(oi.`qty`) AS `add`
FROM `store_inventory` si
LEFT JOIN `override` o
ON o.`ref_id` = si.`store_id`
AND o.`type` = "STORE"
AND o.`action` = "ADD"
AND DATE(o.`dt_created`) = '2018-09-01'
LEFT JOIN `override_items` oi
ON oi.`item_id` = si.`item_id`
AND oi.`ovr_id` = o.`ovr_id`
WHERE si.`store_id` = '4'
GROUP BY si.`item_id`
UNION ALL
-- CANCELLED SALES (ADD)
SELECT si.`item_id`,SUM(sai.`si_qty`) AS `add`
FROM `store_inventory` si
LEFT JOIN `sales` s
ON s.`sales_store_id` = si.`store_id`
AND s.`cancelled_by` IS NOT NULL
AND DATE(s.`dt_cancelled`) = '2018-09-01'
LEFT JOIN `sales_items` sai
ON sai.`si_sales_id` = s.`sales_id`
AND sai.`si_item_id` = si.`item_id`
WHERE si.`store_id` = '4'
GROUP BY si.`item_id`
UNION ALL
-- PULLOUT REJECTED ADDED BACK TO STORE (ADD)
SELECT si.`item_id`,SUM(poi.`poi_actual`) AS `add`
FROM `store_inventory` si
LEFT JOIN `pullout` p
ON p.`pullout_reason` IN ("STORE TO DAMAGE","STORE TO WAREHOUSE")
AND p.`pullout_status` IN ("REJECT","HEAD-REJECTED")
AND DATE(p.`dt_modified`) = '2018-09-01'
AND p.`pullout_from` = si.`store_id`
LEFT JOIN `pullout_items` poi
ON poi.`poi_item_id` = si.`item_id`
AND poi.`poi_pullout_id` = p.`pullout_id`
WHERE si.`store_id` = '4'
GROUP BY si.`item_id`
) AS add_temp
GROUP BY `item_id`
As you can see i loop all my table from my store inventory items this is only a one day report because i do the loop in php for date ranges. Im wondering if this query can be enhanced more. I tried the left join all over my tables and i got no luck. Is this the right query for this kind of reporting? this is just part my query BTW. I still have this openingbalance,damaged,sold,others query as you can see in my SELECT statement. So i really need an advise regarding with this long query. I already added indeces of my columns to my tables in order to select results faster.