Hello I have the follow sql query it works but it is kind of slow
SELECT
ep . *,
t_u.sUsername AS sLockedBy,
epi.sName,
em.sName AS sManufacturerName,
SUM(IF(eop.dInProduction IS NULL
AND eop.dFromProduction IS NULL
AND eop.dShipped IS NULL
AND eop.nIsCancelled = 0
AND eos.sStatusCode NOT IN ('Canceled' , 'Finished', 'Complete'),
1,
0)) AS nProductOrdered,
SUM(IF(eop.dInProduction IS NOT NULL
AND eop.dFromProduction IS NULL
AND eop.dShipped IS NULL
AND eop.nIsCancelled = 0
AND eos.sStatusCode NOT IN ('Canceled' , 'Finished', 'Complete'),
1,
0)) AS nProductInProduction,
SUM(IF(eop.dInProduction IS NOT NULL
AND eop.dFromProduction IS NOT NULL
AND eop.dShipped IS NULL
AND eop.nIsCancelled = 0
AND eos.sStatusCode NOT IN ('Canceled' , 'Finished', 'Complete'),
1,
0)) AS nProductFromProduction,
SUM(IF(eop.dInProduction IS NULL
AND eop.dFromProduction IS NULL
AND eop.dShipped IS NULL
AND eop.nIsCancelled = 0
AND eos.sStatusCode NOT IN ('Canceled' , 'Finished', 'Complete'),
1,
0)) + ep.nInStock AS nStockCheck
FROM
eshop3_products AS ep
LEFT JOIN
users AS t_u ON ep.nUserLockID = t_u.nUID
AND t_u.nDeleted = 0
INNER JOIN
eshop3_products_i18n AS epi ON ep.nUID = epi.nProductID
AND epi.nLangID = 1
AND epi.nDeleted = 0
LEFT JOIN
eshop3_manufacturers AS em ON ep.nManufacturerID = em.nUID
AND em.nDeleted = 0
LEFT JOIN
eshop3_order_products AS eop ON ep.nUID = eop.nProductID
LEFT JOIN
eshop3_orders AS eo ON eop.nOrderID = eo.nUID
LEFT JOIN
eshop3_order_statuses AS eos ON eo.nUID = eos.nOrderID
AND eos.nUID = (SELECT
nUID
FROM
eshop3_order_statuses as eos
WHERE
eo.nUID = eos.nOrderID
ORDER BY eos.nUID DESC
LIMIT 1)
WHERE
(ep.nDeleted = 0)
GROUP BY ep.nUID
ORDER BY ep.sStoreCode ASC
The Product Table has total 462 rows,
The Order Statuses Tables has total 17 154 rows
The execution time of the query is 1.5 secs which I think it is slow.
I use the INNER SELECT in the ON clause to get the last status for the given order, and here I think there is something wrong.
WHen I remove the order statuses table from the whole query the execution time is several times faster 0.152 secs
Could you give me some advice how can I optimize the query I have
Here you go the sql with explain
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY epi ALL nProductID 408 Using where; Using temporary; Using filesort
1 PRIMARY ep eq_ref PRIMARY,nUID PRIMARY 4 dragoni_zfms.epi.nProductID 1 Using where
1 PRIMARY em eq_ref PRIMARY PRIMARY 4 dragoni_zfms.ep.nManufacturerID 1
1 PRIMARY t_u eq_ref PRIMARY PRIMARY 4 dragoni_zfms.ep.nUserLockID 1
1 PRIMARY eop ref id_productid id_productid 5 dragoni_zfms.ep.nUID 13
1 PRIMARY eo eq_ref PRIMARY PRIMARY 4 dragoni_zfms.eop.nOrderID 1 Using index
1 PRIMARY eos eq_ref PRIMARY,nOrderID PRIMARY 4 func 1
2 DEPENDENT SUBQUERY eos ref nOrderID nOrderID 4 dragoni_zfms.eo.nUID 1 Using where; Using index; Using filesort