select lot_id, max(claim_time)claim_time, count(case when(ope_category='Ship')then lot_id else null end) as LS, count(case when(ope_category='Unship') then lot_id else null end) as LUS from f3rpt.F3_TB_DAILY_FABOUT where substr(lot_id,1,2) not in('CA','CW','ES','E0','EM') and lot_type = 'Production' AND LOT_ID NOT LIKE 'H%' and substr(lot_id,7,4)='.00F' and ope_category in ('Ship','Unship') and year(claim_time) = year(current date - 1 days) and month(claim_time) = month(current date - 1 days) group by lot_id) as a where LS - LUS > 0 ，以上sql如何优化

这个SQL语句中，可以优化的地方如下：

1. 在WHERE子句中，使用函数year()和month()可能导致索引失效，可以考虑将其改为claim_time的范围查询，如下所示：

AND claim_time >= DATE(current date - 1 month) AND claim_time < DATE(current date)

2. 在COUNT函数中，使用CASE语句进行条件统计，可以改为使用SUM函数，如下所示：

SUM(CASE WHEN ope_category='Ship' THEN 1 ELSE 0 END) AS LS
SUM(CASE WHEN ope_category='Unship' THEN 1 ELSE 0 END) AS LUS

3. 在WHERE子句中，使用了聚合函数，将查询结果限制在LS-LUS>0的记录，这种方式不利于索引的使用，可以考虑使用HAVING子句，如下所示：

HAVING LS > LUS

4. 在子查询中，只需要查询claim_time的最大值，可以使用MAX函数来代替ORDER BY和LIMIT 1子句，如下所示：

MAX(claim_time) AS claim_time

综上所述，优化后的SQL语句如下：

SELECT lot_id, MAX(claim_time) AS claim_time, 
       SUM(CASE WHEN ope_category='Ship' THEN 1 ELSE 0 END) AS LS, 
       SUM(CASE WHEN ope_category='Unship' THEN 1 ELSE 0 END) AS LUS
FROM f3rpt.F3_TB_DAILY_FABOUT
WHERE substr(lot_id,1,2) NOT IN ('CA','CW','ES','E0','EM') 
  AND lot_type = 'Production' 
  AND LOT_ID NOT LIKE 'H%' 
  AND substr(lot_id,7,4)='.00F' 
  AND ope_category IN ('Ship','Unship') 
  AND claim_time >= DATE(current date - 1 month) AND claim_time < DATE(current date)
GROUP BY lot_id
HAVING LS > LUS;