Mybatis中@Param注解的作用说明

public List<Role> findRoleByMap(Map<String, Object> parameter);

<select id="findRoleByMap" parameterType="map" resultType="role">
    SELECT id,name FROM t_role
    WHERE roleName=#{roleName}
    AND note=#{note}
<select>

RoleMapper roleMapper = sqlSession.getMapper(RoleMapper.class);
Map<String, Object> parameter = new HashMap<>();
parameter.put("roleName", "剑士");
parameter.put("note", "决战紫禁之巅");
List<Role> roles = roleMapper.findRolesByMap(parameter);

public List<Role> findRoleByAnnotation(@Param("roleName") String roleName, @Param("note") String note);

public class RoleParam {
    private String roleName;
    private String note;
    /*getter和setter*/
}

public List<Role> findRoleByBean(RoleParam role);

public List<Role> findRoleByMix(@Param("roleP") RoleParam role, @Param("permissionP") PermissionParam permission);

<select id="findRoleByMix" resultType="role">
    SELECT id,name FROM t_role
    WHERE roleName=#{roleP.roleName}
    AND note=#{rolep.note}
    AND level=#{permissionP.level}
<select>

@Select("select column from table where userid = #{userid} ")
public int selectColumn(int userid);

@Select("select column from table where userid = ${userid} ")
public int selectColumn(@Param("userid") int userid);

@Select("select column from table where userid = ${userid} ")
public int selectColumn(@Param("userid") int userid);

// 这里id是user的属性
@Select("SELECT * from Table where id = ${id}")
Enchashment selectUserById(User user);