修复住宿：增加并发床位分配串行保护

RuoYi-Vue/ruoyi-train/src/main/java/com/ruoyi/train/mapper/TrainDormitoryInfoMapper.java

@@ -21,6 +21,14 @@ public interface TrainDormitoryInfoMapper
      */
     public TrainDormitoryInfo selectTrainDormitoryInfoByDormId(String dormId);
 
+    /**
+     * 查询宿舍信息并加行级排他锁 (SELECT ... FOR UPDATE)
+     *
+     * @param dormId 宿舍信息主键
+     * @return 宿舍信息
+     */
+    public TrainDormitoryInfo selectTrainDormitoryInfoForUpdate(@Param("dormId") String dormId);
+
     /**
      * 查询宿舍信息列表 (包含实时聚合的 used_count 与 remaining_beds)
      *

RuoYi-Vue/ruoyi-train/src/main/resources/mapper/train/TrainDormitoryInfoMapper.xml

@@ -76,6 +76,27 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         WHERE d.dorm_id = #{dormId} AND d.del_flag = '0'
     </select>
 
+    <select id="selectTrainDormitoryInfoForUpdate" parameterType="String" resultMap="TrainDormitoryInfoResult">
+        SELECT
+            dorm_id,
+            dorm_building,
+            dorm_floor,
+            dorm_room,
+            capacity,
+            gender_type,
+            lock_device_sn,
+            dorm_status,
+            del_flag,
+            create_by,
+            create_time,
+            update_by,
+            update_time,
+            remark
+        FROM train_dormitory_info
+        WHERE dorm_id = #{dormId} AND del_flag = '0'
+        FOR UPDATE
+    </select>
+
     <select id="checkBuildingRoomUnique" resultMap="TrainDormitoryInfoResult">
         SELECT dorm_id, dorm_building, dorm_room
         FROM train_dormitory_info