目录
Mybatis中常用的注解
注解 | 目标 | 对应的XML标签 |
@CacheNamespace | 类 | <cache> |
@CacheNamespaceRef | 类 | <cacheRef> |
@Results | 方法 | <resultMap> |
@Result | 方法 | <result> <id> |
@One | 方法 | <association> |
@Many | 方法 | <collection> |
@Insert @Update @Delete | 方法 | <insert> <update> <delete> |
@InsertProvider @UpdateProvider @DeleteProvider @SelectProvider | 方法 | <insert> <update> <delete> <select> 允许创建动态SQL |
@Param | 参数 | N/A |
@Options | 方法 | 映射语句的属性 |
@select | 方法 | <select> |
使用案例
(1)@Select 简单查询
@Select(" Select * from user ")
@Results({
@Result(id = true, column = "id", property = "id"),
@Result(column = "name", property = "name"),
@Result(column = "tel", property = "tel"),
@Result(column = "birth", property = "birth"),
@Result(column = "address", property = "address")
})
List<User> queryAllUser();
(2)@Insert 简单插入
@Insert(" insert into user(name,sex,age) values(#{name},#{sex},#{age} " )
int saveUser(User user);
(3)@Update 简单更新
@Update("update user set name= #{name} ,sex = #{sex},age =#{age} where id = #{id}")
void updateUserById(User user);
(4)@Delete 简单删除
@Delete("delete from user where id =#{id} ")
void deleteById(Integer id);
(5)@One
@Select(" select * from user where id = #{id} ")
@Results(
value = {
@Result(column = "name",property = "name"),
@Result(column = "type",property = "type",
//one指示我们,查询出来的结果只有一个。
one = @One(select="com.xxxx.UserMapper.findTypeById",
//及时加载
fetchType = FetchType.EAGER))
}
)
User findUserById(Integer id);
(6)@Many
@Select(" select * from dept")
@Results({
@Result(id = true, column = "did", property = "did"),
@Result(column = "name", property = "name"),
@Result(column = "address", property = "address"),
@Result(column = "id",property = "emps",
//many指示我们,查询出来的结果有很多个
many = @Many(
//select = sql语句
select = "com.xxxx.EmpMapper.findAllEmpByDid",
//懒加载
fetchType = FetchType.LAZY))
})
List<Dept> findAllDept();
转自:https://www.cnblogs.com/uiee/p/10778694.html
表示感谢!!!
@Results、@Result、@ResultMap注解的使用是为了解决实体类名称和数据库名称不一致的问题,使用方法参考如下博客: