EntityWrapper类

1、EntityWrapper

Mybatis-Plus 通过 EntityWrapper 来让用户自由的构建查询条件，简单便捷

2、selectPage方法

@Test
public void testEntityWrapperSelect(){
    //分页查询 tbl_employee 表中，年龄在 18~50 之间性别为男且 姓名为 xx 的所有用户
    List employees = employeeMapper.selectPage(new Page<>(1, 3),
            new EntityWrapper()
                    .between("age", 18, 50)
                    .eq("gender", 1)
                    .eq("last_name", "Tom")
    );
    for(Employee e:employees){
        System.out.println(e);
    }
}

3、selectList方法

List emps = employeeMapper.selectList(
new EntityWrapper()
.eq("gender", 0)
.like("last_name", "老师")
//.or()    // SQL: (gender = ? AND last_name LIKE ? OR email LIKE ?)    
.orNew()   // SQL: (gender = ? AND last_name LIKE ?) OR (email LIKE ?) 
.like("email", "a")
);

4、update()

@Test
    public void testEntityWrapperUpdate() {
        
        Employee employee = new Employee();
        employee.setLastName("苍老师");
        employee.setEmail("cls@sina.com");
        employee.setGender(0);
        
        
        employeeMapper.update(employee, 
                    new EntityWrapper()
                    .eq("last_name", "Tom")
                    .eq("age", 44)
                    );
    }

5、delete方法

@Test
    public void testEntityWrapperDelete() {
        
        employeeMapper.delete(
                    new EntityWrapper()
                    .eq("last_name", "Tom")
                    .eq("age", 22)
                );