mybatis 基本操作 & 删除 插入 更新 查询

 根据主键删除数据

 

插入数据

 -- ================插入=================
insert into  emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time) values (
    'tom','塔姆','tom',1 , '1.png' ,now(),1,now(),now()

 

@Options(keyProperty = "id",useGeneratedKeys = true)
@Insert("insert into  emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time) " +
              "values ( #{username},#{name},#{gender},#{image},#{job},#{entrydate},#{deptId},#{createTime},#{updateTime})")

    public void  insert(Emp emp);

 

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Emp {
    private Integer id;   // Id
    private String username;  //用户名
    private String password; //用户密码
    private String name ;    //姓名
    private short gender;   //性别 1男  2女
    private String image;    //头像 url
    private  short job ;      // 工作职位  1班主任  2讲师   3 学工主管  4 教研主管 5 咨询师
    private LocalDate entrydate ;  //入职时间
    private Integer deptId;        // 部门ID
    private LocalDateTime createTime;  //创建时间
    private LocalDateTime updateTime;   // 修改时间

    @Test
public void testInsert(){
        //构造员工对象
        Emp emp =new Emp();
      emp.setUsername("tom2");
      emp.setName("塔姆");
      emp.setImage("1.jpg");
      emp.setGender((short)1);
      emp.setJob((short)1);
      emp.setEntrydate(LocalDate.of(2000,1,1));
      emp.setCreateTime(LocalDateTime.now());
      emp.setUpdateTime(LocalDateTime.now());
      emp.setDeptId(1);

      empMapper.insert(emp);
        System.out.println(emp.getId());
}

更新数据

查询数据

 

如果数据里的名字和实体类的名·不一样重名为新的名字重名

//的一种
@Select("select id, username, password, name, gender, image, job, entrydate, dept_id deptId, create_time createTime, update_time updateTime from emp where id=#{di}")
    public  Emp getById (Integer id);
//第二种
    @Results({
            @Result(column = "dept_id", property = "deptId"),
            @Result(column = "create_time", property= "createTime"),
            @Result(column = "update_time", property= "updateTime"),
    })
    @Select("select * from emp where id=#{id}")
    public Emp getById(Integer id);

#开启 mybatis的驼峰命名自动映射开关    变成 a_column--->aColumn
mybatis.configuration.map-underscore-to-camel-case=true

条件查询

 @Select("select *  from  emp  where name like concat('%','#{name}','%') and  " +
           "gender=#{gender} and  entrydate between#{begin} and #{end} order by update_time desc ;")
    public List list(String name, Short gender, LocalDate begin ,LocalDate end);

 @Test
    public void testList(){
     List empList= empMapper.list("张",(short)1,LocalDate.of(2010,1,1)
            ,LocalDate.of(2020,1,1));
        System.out.println(empList);
    }