select d.id,d.tempcode,d.tempname,d.isvalid,d.startdate,d.enddate,d.creater,d.creattime,d.usestate,d.state from fo_temp d where d.state = 0 and now() between d.startdate and d.enddate and d.tempcode like '%%划%%' or d.tempname like '%%划%%' and not exists(select 1 from chr_path_fo p where p.tempcode = d.tempcode and p.state !=9 order by d.id desc) 优化
时间: 2024-04-05 08:34:10 浏览: 17
为了优化这个 SQL 查询语句,我们需要注意操作符的优先级和逻辑关系。根据操作符优先级,AND 运算符的优先级高于 OR 运算符,所以需要使用括号明确表达逻辑关系。
另外,我们还可以使用索引来加速 LIKE 模糊匹配操作。可以为 tempcode 和 tempname 字段创建索引,这样可以加速查询匹配。
优化后的 SQL 查询语句如下:
SELECT d.id, d.tempcode, d.tempname, d.isvalid, d.startdate, d.enddate, d.creater, d.creattime, d.usestate, d.state
FROM fo_temp d
LEFT JOIN chr_path_fo p ON p.tempcode = d.tempcode AND p.state != 9
WHERE d.state = 0
AND NOW() BETWEEN d.startdate AND d.enddate
AND (d.tempcode LIKE '%划%' OR d.tempname LIKE '%划%')
AND p.tempcode IS NULL
ORDER BY d.id DESC;
这样就可以实现更高效的查询了。同时,为了进一步提高查询效率,可以考虑将 LIKE 操作改为全文搜索,使用全文搜索引擎来实现更快速、更准确的匹配。
相关问题
select d.id,d.tempcode,d.tempname,d.isvalid,d.startdate,d.enddate,d.creater,d.creattime,d.usestate,d.state from fo_temp d where d.state = 0 and now() between d.startdate and d.enddate and not exists(select 1 from chr_path_fo p where p.tempcode = d.tempcode and p.state !=9 order by d.id desc) 优化
为了优化这个 SQL 查询语句,我们可以对其中的子查询进行优化。可以将子查询改为使用 LEFT JOIN 操作,同时使用 IS NULL 条件判断来过滤掉不匹配的行,这样可以减少子查询的执行次数,提高查询效率。
优化后的 SQL 查询语句如下:
SELECT d.id, d.tempcode, d.tempname, d.isvalid, d.startdate, d.enddate, d.creater, d.creattime, d.usestate, d.state
FROM fo_temp d
LEFT JOIN chr_path_fo p ON p.tempcode = d.tempcode AND p.state != 9
WHERE d.state = 0
AND NOW() BETWEEN d.startdate AND d.enddate
AND p.tempcode IS NULL
ORDER BY d.id DESC;
这样就可以实现更高效的查询了。
AttributeError: 'SPIDER' object has no attribute 'tempcode'
回答: 这个错误是由于在代码中引用了一个对象的属性或方法,但是该对象并没有定义这个属性或方法。根据给出的引用内容,我们可以看到有一个AttributeError,显示"'SPIDER' object has no attribute 'tempcode'"。这意味着在名为SPIDER的对象中,没有定义名为tempcode的属性。要解决这个错误,你需要检查代码,确保SPIDER对象中定义了tempcode属性。如果没有定义,需要添加相应的属性或方法来解决这个错误。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
#### 引用[.reference_title]
- *1* *2* [AttributeError: XX object has no attribute XX问题案例分享](https://blog.csdn.net/jinhoward/article/details/124721999)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT0_1"}}] [.reference_item style="max-width: 50%"]
- *3* [如何修复python中的“AttributeError:type object has no attribute”?](https://blog.csdn.net/weixin_39835178/article/details/111443339)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v92^chatsearchT0_1"}}] [.reference_item style="max-width: 50%"]
[ .reference_list ]
相关推荐
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![txt](https://img-home.csdnimg.cn/images/20210720083642.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)