7.MySQL数据库之数据过滤

朴灿烈づ我的快乐病毒、 2023-06-17 14:56 14阅读 0赞

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## MySQL数据库之数据过滤 ##

### 一、组合where条件 ###

数据库：own ->>表：single\_pro

关键点：使用and或者or连接。

1.说明：检索counted大于50并且downloadcount小于10000的所有数据。

select counted,downloadcount from single_pro where counted >50 and downloadcount <10000;

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw_size_16_color_FFFFFF_t_70][]

2.说明：检索counted等于50或者downloadcount大于10000的所有数据。

select counted,downloadcount from single_pro where counted =50 or 10000< downloadcount;

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw_size_16_color_FFFFFF_t_70 1][]

3.说明：检索counted=50或者counted=97并且downloadcount大于100的数据。

【一定要注意，and的优先级高于or，需要使用小括号将优先级改变】

select counted,downloadcount from single_pro where (counted=50 or counted=97) and 100< downloadcount;

![20191129150445596.png][]

### 二、in操作符 ###

in操作符与or操作符功能相同，但是优点更加明显。

select counted,downloadcount from single_pro where counted in(50,97) and 100< downloadcount;

![20191129151029522.png][]

### 三、not操作符 ###

否定后面跟着的条件，除了后面的条件之外的都满足要求。

说明：counted不小于100并且downloadcount 大于100。

select counted,downloadcount from single_pro where not counted <100 and 100< downloadcount;

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw_size_16_color_FFFFFF_t_70 2][]

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20191129145844136.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw==,size_16,color_FFFFFF,t_70
[20191129150445596.png]: https://img-blog.csdnimg.cn/20191129150445596.png
[20191129151029522.png]: https://img-blog.csdnimg.cn/20191129151029522.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20191129151401460.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjgzMDY5Nw==,size_16,color_FFFFFF,t_70