feat:完善通过门户创建课程。1.在课程PO与DTO中加入教师门户PID，为实现后续删改查提供基础。2.完善PO、VO、DTO类型转换逻辑

src/main/java/com/njuzr/eaibackend/dto/course/CourseDTO.java

@@ -18,9 +18,6 @@ public class CourseDTO {
     @NotNull(message = "课程名不能缺失")
     private String courseName;
 
-    @NotNull(message = "老师Id不能缺失")
-    private List<Long> teacherIds;
-
     private List<String> courseImages;
 
     private String targetGrade;
@@ -38,4 +35,8 @@ public class CourseDTO {
 
     @NotNull(message = "选课码不能缺失")
     private String enrollCode; // 选课码
+
+    private List<Long> teacherIds; // 教师EAI ID
+
+    private String teacherPid; // 教师门户ID
 }

src/main/java/com/njuzr/eaibackend/mapper/UserMapper.java

@@ -48,6 +48,13 @@ public interface UserMapper extends BaseMapper<User> {
      */
     String selectNameById(Long id);
 
+    /**
+     * 通过用户PID查询用户名字
+     * @param pid
+     * @return 姓名
+     */
+    String selectNameByPid(Long pid);
+
     /**
      * 通过邮箱读取用户
      * @param officialEmail

src/main/java/com/njuzr/eaibackend/po/Course.java

@@ -25,6 +25,9 @@ public class Course {
 
     @TableField("teacher_ids")
     private String teacherIds; // 序列化好的字符串
+    
+    @TableField("teacher_portal_id")
+    private String teacherPid;
 
     @TableField("enroll_code")
     private String enrollCode; //选课码

src/main/resources/mapper/UserMapper.xml

@@ -49,4 +49,10 @@
         from users
         where id = #{id}
     </select>
+
+    <select id="selectNameByPid" resultType="String">
+        select name
+        from users
+        where pid = #{pid}
+    </select>
 </mapper>