MyBatisPlus条件构造器

一、带条件的查询操作

selectPage

分页使用

QueryWrapper

通过

QueryWrapper

封装查询条件，返回符合查询条件的分页对象

@Test
    public void testQueryWrapper(){
        Page<Employee> employeePage = employeeMapper.selectPage(new Page<Employee>(1, 2),
                new QueryWrapper<Employee>()
                        .between("age", 30, 50)
                        .eq("gender", 0)
                        .eq("last_name", "mpTestInsert")
        );

        Object[] records = employeePage.getRecords().toArray();
        int start = (int) ((employeePage.getCurrent() - 1) * employeePage.getSize());
        int end = (int) (start + employeePage.getSize());
        for (int i = start; i < end; i++){
            System.out.println(records[i]);
        }
    }
           

打印日志：

selectList

方法使用

QueryWrapper

@Test
    public void testSelectList(){
        List<Employee> employees = employeeMapper.selectList(new QueryWrapper<Employee>()
                .eq("gender", 0)
                .like("last_name", "%老师%")
                .or()
                .like("email", "%a%")
        );

        for (Employee employee : employees){
            System.out.println(employee);
        }

    }
           

打印日志：

二、带条件的修改操作

update

方法使用

QueryWrapper

@Test
    public void testUpdateQueryWrapper(){
        Employee employee = new Employee();
        employee.setLastName("updateTest");
        employee.setGender(1);
        employee.setEmail("[email protected]");

        int update = employeeMapper.update(employee, new QueryWrapper<Employee>()
                .eq("last_name", "mpTestInsert")
                .eq("age", 45)
        );

        System.out.println(update);
    }
           

打印日志：

三、带条件的删除操作

delete

方法使用

QueryWrapper

@Test
    public void testDeleteQueryWrapper(){
        int delete = employeeMapper.delete(new QueryWrapper<Employee>()
                .eq("last_name", "mpTestInsert")
                .eq("age", 66)
        );

        System.out.println(delete);
    }
           

打印日志：

四、QueryWrapper常用方法

条件构造器所有的条件方法