Mybatis的注解们
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用例：
@Insert("INSERT INTO student(name,math,eng) VALUES (#{name},#{math}, #{eng})")
void insert(Student student);
@Delete(" delete from student where id=#{id}")
void delete(int id);
@Update("update student set name=#{name}, math=#{math}, eng=#{eng} where id =#{id}")
void update(Student student);
@Select(" select * from student where id=#{id}")
Student findByID(int id);
Results 、Result
@Select("select *,o.uid as UserID ,o.id as OrderID from user as u inner join orders as o on o.uid=u.id order by u.id")
@Results({
@Result(column = "OrderID",property = "id"),
@Result(column = "ordertime",property = "ordertime"),
@Result(column = "total",property = "total"),
@Result(column = "UserID",property = "user.id"),
@Result(column = "name",property = "user.name"),
@Result(column = "password",property = "user.password")})
List findAll();
【Mybatis(四)|Mybatis(四) 注解】基于注解的多对多查询
思路就是分两步查询，查出User表中所有用户，然后再使用用户的id去和中间表和role表联查，将结果封装在User的ROLElIST中。详见下：
UserMapper接口
@Select("select * from user")
@Results({
@Result(id = true,column = "id",property = "id"),
@Result(column = "name",property = "name"),
@Result(column = "password", property = "password"),
@Result(
property = "RoleList",//放到哪里，即user类中的哪个属性
column = "id",//拿谁去查,就是用userID传参
javaType = List.class, //该属性的类型
//一对一就是@One，一对多就是@Many
many = @Many(select = "com.dao.RoleMapper.findByUID")//调用其他查询方法，该方法需要传入int id的参数
)
})
List findUserAndRole();
RoleMapper
@Select("select * from role_user as ru,role as r where ru.roleid=r.id and ru.userid=#{id}")
List findByUID(int id);
测试结果如下：
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