Mybatis 常用注解

Mybatis常用注解对应的目标和标签如表所示:

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>

@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();

@Insert 简单插入

@Insert(" insert into user(name,sex,age) values(#{name},#{sex},#{age} " )
int saveUser(User user);

@Update 简单更新

@Update("update user set name= #{name} ,sex = #{sex},age =#{age} where id = #{id}")
void updateUserById(User user);

@Delete 简单删除

@Delete("delete from  user  where id =#{id} ")
void deleteById(Integer id);

@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);

@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();