add 乐团学生列表增加，声部更换详情

mec-biz/src/main/java/com/ym/mec/biz/service/impl/SubjectChangeServiceImpl.java

@@ -246,8 +246,10 @@ public class SubjectChangeServiceImpl extends BaseServiceImpl<Integer, SubjectCh
         if (subjectChange.getChangeMusical() != null) {
             goodsIds += subjectChange.getChangeMusical() + "";
         }
-        if (subjectChange.getChangeAccessories() != null) {
+        if (StringUtils.isNotBlank(subjectChange.getChangeAccessories())) {
             goodsIds += StringUtils.isNotBlank(goodsIds) ? "," + subjectChange.getChangeAccessories() : subjectChange.getChangeAccessories();
+        }else {
+            subjectChange.setChangeAccessories(null);
         }
         BigDecimal goodsPrice = BigDecimal.ZERO;
         List<Goods> goodies = goodsDao.findGoodsByIds(goodsIds);