[英]Can the query be Improved as it is going for timeout exception
由于超时异常,如何改进查询。 有人可以帮助我改善查询结果吗?
UPDATE pdtdeliveryTable p SET p.OrderID = IFNULL
(
(SELECT OrderID from OrderTable o where o.DiagramID=p.DiagramID AND o.DeliveryDate=
(
Select min(o2.DeliveryDate) from OrderTable o2 where o2.DiagramId=o.DiagramID Order by o2.DeliveryDate
)Limit 1),0
)
where p.OrderID=0;
尝试这个:
UPDATE pdtdeliveryTable p
LEFT OUTER JOIN (SELECT o.DiagramID, o.OrderID FROM OrderTable o
INNER JOIN ( SELECT DiagramID, MIN(DeliveryDate) DeliveryDate
FROM OrderTable GROUP BY DiagramID
) AS A ON o.DiagramID = A.DiagramID AND o.DeliveryDate = A.DeliveryDate
) AS A ON A.DiagramID = p.DiagramID
SET p.OrderID = IFNULL(A.OrderID, 0);
要么
UPDATE pdtdeliveryTable p
LEFT OUTER JOIN ( SELECT DiagramID, OrderID
FROM (SELECT DiagramID, OrderID, DeliveryDate FROM OrderTable ORDER BY DiagramID, DeliveryDate) AS A
GROUP BY DiagramID
) AS A ON p.DiagramID = A.DiagramID
SET p.OrderID = IFNULL(A.OrderID, 0);
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