优化SQL SELECT k.kind, SUM(production_year = 2005) AS Count2005, SUM(production_year = 2006) AS Count2006, SUM(production_year = 2007) AS Count2007, SUM(production_year = 2008) AS Count2008, SUM(production_year = 2009) AS Count2009 FROM title t JOIN kind_type k ON k.id = t.kind_id GROUP BY t.kind_id ORDER BY NULL;

这个查询语句看起来已经相当简洁和高效了。但是，如果您的数据库中的数据量很大，您可能会考虑一些优化策略来提高查询性能。下面是一些可能的优化方法：

1. 索引：确保在title表的kind_id列和kind_type表的id列上创建了适当的索引。这样可以加快连接操作的速度。

2. 覆盖索引：如果可能的话，尝试将索引覆盖所需的列。这样可以避免对数据表的实际访问，从而提高查询性能。

3. 预先计算：如果生产年份（production_year）的范围是固定的，并且不会更改，那么您可以在一个子查询或临时表中预先计算每个年份的计数。这样，您就不需要使用条件表达式和SUM函数，而是直接从预先计算的结果中选择。

4. 分区表：如果您的数据表很大，可以考虑将其分区。将数据分为更小的逻辑部分可以提高查询性能。

5. 查询缓存：如果您经常执行相同的查询，数据库服务器可能会使用查询缓存来提高性能。确保查询缓存功能已启用。

根据您的具体情况和数据库系统，这些优化方法可能有所不同。请根据您的需求和环境选择适合您的方法。

希望这些信息对您有所帮助！如果您还有其他问题，请随时提问。

相关问题

SELECT b.CallerNum, b.Duration duration, min(b.CRT_TIME_) abnormalTime, count(b.CallerNum) abnormalCallNumber, count(b.CallerNum) abnormalCallTotal FROM basebill b left join billdetails b2 on b.base_bill_id =b2.base_bill_id where b2.area_code_ != 86 and b.billType = 1 and b.IS_DELETE_ = 0 and b.CRT_TIME_ >= '2023-06-06 13:00:00' and b.CRT_TIME_ <= '2023-06-06 15:00:00' and ( (b.Duration >=900) or (b.CallerNum in (SELECT b.CallerNum FROM basebill b left join billdetails b2 on b.base_bill_id =b2.base_bill_id where b2.area_code_ != 86 and b.billType = 1 and b.IS_DELETE_ = 0 and b.CRT_TIME_ >= '2023-06-06 13:00:00' and b.CRT_TIME_ <= '2023-06-06 15:00:00' GROUP BY b.CallerNum HAVING COUNT(b.CallerNum) >= 5)) or ((SELECT COUNT(*) FROM basebill b1 left join billdetails b2 on b1.base_bill_id =b2.base_bill_id where b2.area_code_ != 86 and b1.billType = 1 and b1.IS_DELETE_ = 0 and b1.CRT_TIME_ >= '2023-06-06 13:00:00' and b1.CRT_TIME_ <= '2023-06-06 15:00:00' and b1.CallerNum = b.CallerNum ) >= 10) ) group by b.CallerNum优化这条sql的查询速度，具体做法

具体做法如下：

1. 对where条件中的字段建立索引：针对b2.area_code_、b.billType、b.IS_DELETE_、b.CRT_TIME_、b.Duration、b.CallerNum等字段建立相应的索引，可以提高查询效率。

2. 避免使用子查询：将子查询改写成join操作，可以提高查询速度。例如：

SELECT b.CallerNum, b.Duration duration, min(b.CRT_TIME_) abnormalTime, count(b.CallerNum) abnormalCallNumber, count(b.CallerNum) abnormalCallTotal 
FROM basebill b 
LEFT JOIN billdetails b2 ON b.base_bill_id = b2.base_bill_id 
LEFT JOIN (SELECT CallerNum, COUNT(*) AS cnt FROM basebill WHERE IS_DELETE_ = 0 AND CRT_TIME_ >= '2023-06-06 13:00:00' AND CRT_TIME_ <= '2023-06-06 15:00:00' GROUP BY CallerNum HAVING COUNT(*) >= 5) AS t1 ON b.CallerNum = t1.CallerNum 
LEFT JOIN (SELECT CallerNum, COUNT(*) AS cnt FROM basebill WHERE IS_DELETE_ = 0 AND CRT_TIME_ >= '2023-06-06 13:00:00' AND CRT_TIME_ <= '2023-06-06 15:00:00' GROUP BY CallerNum HAVING COUNT(*) >= 10) AS t2 ON b.CallerNum = t2.CallerNum 
WHERE b2.area_code_ != 86 AND b.billType = 1 AND b.IS_DELETE_ = 0 AND b.CRT_TIME_ >= '2023-06-06 13:00:00' AND b.CRT_TIME_ <= '2023-06-06 15:00:00' AND (b.Duration >= 900 OR t1.CallerNum IS NOT NULL OR t2.CallerNum IS NOT NULL) 
GROUP BY b.CallerNum

3. 避免重复查询：在where条件和select语句中都有重复查询的情况，可以将重复查询的部分提取出来，减少查询次数。例如：

SELECT b.CallerNum, b.Duration duration, min(b.CRT_TIME_) abnormalTime, count(b.CallerNum) abnormalCallNumber, count(b.CallerNum) abnormalCallTotal 
FROM basebill b 
LEFT JOIN billdetails b2 ON b.base_bill_id = b2.base_bill_id 
LEFT JOIN (SELECT CallerNum, COUNT(*) AS cnt FROM basebill WHERE IS_DELETE_ = 0 AND CRT_TIME_ >= '2023-06-06 13:00:00' AND CRT_TIME_ <= '2023-06-06 15:00:00' GROUP BY CallerNum HAVING COUNT(*) >= 5) AS t1 ON b.CallerNum = t1.CallerNum 
LEFT JOIN (SELECT CallerNum, COUNT(*) AS cnt FROM basebill WHERE IS_DELETE_ = 0 AND CRT_TIME_ >= '2023-06-06 13:00:00' AND CRT_TIME_ <= '2023-06-06 15:00:00' GROUP BY CallerNum HAVING COUNT(*) >= 10) AS t2 ON b.CallerNum = t2.CallerNum 
WHERE b2.area_code_ != 86 AND b.billType = 1 AND b.IS_DELETE_ = 0 AND b.CRT_TIME_ BETWEEN '2023-06-06 13:00:00' AND '2023-06-06 15:00:00' AND (b.Duration >= 900 OR t1.CallerNum IS NOT NULL OR t2.CallerNum IS NOT NULL) 
GROUP BY b.CallerNum, b.Duration, abnormalTime

4. 分批查询：将查询时间段分成多个小段，避免一次查询过多数据，导致查询速度变慢。

5. 对于大表使用分区表：如果表中数据量较大，可以将表进行分区，以提高查询效率。

6. 定期清理无用数据：定期清理已经无用的数据，可以减少查询时的数据量，提高查询速度。

综上所述，以上优化方案可以针对不同的情况进行选择，以提高SQL语句的查询速度。

select t1.month_id, count(distinct case when t1.offer_type_name='主套餐' then offer_name end) aa, count(distinct case when t1.offer_type_name='促销' then offer_name end) bb, count(distinct case when t1.offer_type_name='可选包' then offer_name end) cc, count(distinct case when t2.offer_type_name='主套餐' then offer_name end) aaa, count(distinct case when t2.offer_type_name='促销' then offer_name end) bbb, count(distinct case when t2.offer_type_name='可选包' then offer_name end) ccc, from zone_crmchk.dwd_sum_zhuliuxxsc t1 left join zone_crmchk.dwd_sum_zhuliuxxsc t2 on t2.month < t1.month group by t1.month, count(distinct case when offer_type_name='主套餐' then offer_name end) aa, count(distinct case when offer_type_name='促销' then offer_name end) bb, count(distinct case when offer_type_name='可选包' then offer_name end) cc

根据您提供的 SQL 查询语句，我发现其中存在一个逗号(,)出现在了 FROM 子句之后，这是一个语法错误。您需要将逗号(,)删除，同时将查询语句修改为如下形式：

SELECT
    t1.month_id, 
    COUNT(DISTINCT CASE WHEN t1.offer_type_name='主套餐' THEN offer_name END) aa, 
    COUNT(DISTINCT CASE WHEN t1.offer_type_name='促销' THEN offer_name END) bb, 
    COUNT(DISTINCT CASE WHEN t1.offer_type_name='可选包' THEN offer_name END) cc, 
    COUNT(DISTINCT CASE WHEN t2.offer_type_name='主套餐' THEN offer_name END) aaa, 
    COUNT(DISTINCT CASE WHEN t2.offer_type_name='促销' THEN offer_name END) bbb, 
    COUNT(DISTINCT CASE WHEN t2.offer_type_name='可选包' THEN offer_name END) ccc
FROM 
    zone_crmchk.dwd_sum_zhuliuxxsc t1 
    LEFT JOIN zone_crmchk.dwd_sum_zhuliuxxsc t2 ON t2.month < t1.month 
GROUP BY 
    t1.month_id, 
    COUNT(DISTINCT CASE WHEN offer_type_name='主套餐' THEN offer_name END), 
    COUNT(DISTINCT CASE WHEN offer_type_name='促销' THEN offer_name END), 
    COUNT(DISTINCT CASE WHEN offer_type_name='可选包' THEN offer_name END);

这样修改后，查询语句应该就能正确执行了。