MybatisPlus 条件构造器Wrapper

喜欢ヅ旅行 2023-07-01 08:56 68阅读 0赞

我们来介绍一下mybatis-plus强大的条件构造器。功能是select ...from ... where 中的**where**部分

mybatis-plus的版本为最新版3.0.3 。条件构造器咱们讲述queryWrapper和updateWrapper的用法、关系、以及强大之处。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyMTM5ODg5_size_16_color_FFFFFF_t_70][]

我们做一个测试类：核心语句为：

**QueryWrapper<student> wrapper = new QueryWrapper<student>();  
 wrapper.between("stuNo" ,1, 30).or( i -> i.ge("stuAge",10).le("stuAge", 28));  
 List<student> students =studentmapper.selectList(wrapper);**

public static void test2() {
    		ApplicationContext context =	new ClassPathXmlApplicationContext("applicationContext.xml");
    	    //从ioc中获取mapper
    		StudentMapper studentmapper = (StudentMapper)context.getBean("studentMapper");
    		
    		
    		QueryWrapper<student> wrapper = new QueryWrapper<student>();
    		
    		 //ge 大于等于   le小于等于   lambda表达式  between or ( .ge .le) 相当于加括号
    		 wrapper.between("stuNo" ,1, 30).or( i -> i.ge("stuAge",10).le("stuAge", 28));
    		
    		 List<student> students =studentmapper.selectList(wrapper);
    		 for (student stu : students) {
    			System.out.println(stu.getStuName());}
    	}

![20200120194337110.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyMTM5ODg5_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200120194236104.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyMTM5ODg5,size_16,color_FFFFFF,t_70
[20200120194337110.png]: https://img-blog.csdnimg.cn/20200120194337110.png