如何优化此查询并替换MAX函数？

Question

SELECT MAX(f_orderInteractionID)                
FROM  tOrders O              
INNER JOIN tOrderInteractions  OI    ON OI.fk_orderID = O.f_orderID                
GROUP BY OI.fk_orderID

有没有办法替换max函数，因为在实际执行计划中它使用了Index扫描，我更喜欢使用Index seek。如何改进此查询

Answer 1

要执行此操作，请重试

SELECT f_orderInteractionID
FROM  tOrders O              
INNER JOIN tOrderInteractions  OI    ON OI.fk_orderID = O.f_orderID
ORDER BY f_orderInteractionID DESC
LIMIT 1