Merge pull request #12434 from dataease/pr@dev-v2@refactor_ds_total

refactor(数据集): 优化数据预览条数

core/core-frontend/src/views/visualized/data/dataset/index.vue

@@ -471,6 +471,7 @@ const handleClick = (tabName: TabPaneName) => {
         break
       }
       dataPreviewLoading.value = true
+      total.value = null
       getDatasetPreview(nodeInfo.id)
         .then(res => {
           allFields = (res?.allFields as unknown as Field[]) || []