图书详情的默认封面无法显示问题

src/views/module/bookDetails.vue

@@ -10,7 +10,7 @@
         <div class="book-details-box">
           <div class="book-details">
             <div class="book-cover">
-              <img :src="bookData.cover" :onerror="defaultImg">
+              <img :src="bookData.cover ? bookData.cover : ''" :onerror="defaultImg">
             </div>
             <div class="book-desc">
               <h3>{{ bookData.nbName }}</h3>