diff --git a/apps/desktop/src/components/grid/DataGrid.vue b/apps/desktop/src/components/grid/DataGrid.vue
index 8f598d48fe..b759011f28 100644
--- a/apps/desktop/src/components/grid/DataGrid.vue
+++ b/apps/desktop/src/components/grid/DataGrid.vue
@@ -12092,6 +12092,7 @@ function currentGridContextMenuItems(): ContextMenuItem[] {
               :match-count="searchMatches.length"
               :current-match-index="currentMatchIndex"
               :has-deferred-search-text="!!deferredClientSearchText"
+              :values-truncated="(props.result.large_value_cells?.length ?? 0) > 0"
               @keydown="onSearchKeydown"
               @navigate="navigateMatch"
               @close="closeSearch"
diff --git a/apps/desktop/src/components/grid/DataGridSearchBar.vue b/apps/desktop/src/components/grid/DataGridSearchBar.vue
index 40c42e3873..bf3a1844c0 100644
--- a/apps/desktop/src/components/grid/DataGridSearchBar.vue
+++ b/apps/desktop/src/components/grid/DataGridSearchBar.vue
@@ -12,6 +12,8 @@ const props = defineProps<{
   matchCount: number;
   currentMatchIndex: number;
   hasDeferredSearchText: boolean;
+  /** 结果里含被截断显示的长值（large_value_cells），搜索只覆盖显示文本。 */
+  valuesTruncated?: boolean;
 }>();
 
 const searchText = defineModel<string>("text", { default: "" });
@@ -72,6 +74,11 @@ defineExpose({
           <span>{{ suggestion }}</span>
         </div>
       </div>
+      <!-- 截断标记：表格预览对长文本/JSON 值做服务端截断，客户端搜索只能覆盖
+           显示前缀，匹配数可能少于 SQL 查询（#7279）。 -->
+      <span v-if="props.valuesTruncated && (props.matchCount > 0 || props.hasDeferredSearchText)" data-grid-search-truncated-hint class="text-xs text-amber-600 dark:text-amber-400 shrink-0 cursor-help" :title="t('grid.searchTruncatedValuesHint')" :aria-label="t('grid.searchTruncatedValuesHint')"
+        >≈</span
+      >
       <span v-if="props.matchCount > 0" class="text-xs text-muted-foreground shrink-0">{{ props.currentMatchIndex + 1 }}/{{ props.matchCount }}</span>
       <span v-else-if="props.hasDeferredSearchText" class="text-xs text-muted-foreground shrink-0">0</span>
       <button
diff --git a/apps/desktop/src/components/grid/__tests__/DataGridContextExtractor.spec.ts b/apps/desktop/src/components/grid/__tests__/DataGridContextExtractor.spec.ts
index 1bdab14825..181b65382d 100644
--- a/apps/desktop/src/components/grid/__tests__/DataGridContextExtractor.spec.ts
+++ b/apps/desktop/src/components/grid/__tests__/DataGridContextExtractor.spec.ts
@@ -321,6 +321,33 @@ describe("DataGrid context menu target lifecycle", () => {
     expect(contextMenuLabels()).toContain("Filter");
   });
 
+  async function openGridSearchAndType(host: HTMLElement, query: string) {
+    await settle();
+    const gridRoot = host.querySelector<HTMLElement>("[data-grid-root]");
+    if (!gridRoot) throw new Error("Grid root not found");
+    gridRoot.dispatchEvent(new KeyboardEvent("keydown", { key: "f", ctrlKey: true, bubbles: true, cancelable: true }));
+    await settle();
+    const input = host.querySelector<HTMLInputElement>("input[type=search]");
+    if (!input) throw new Error("Search input not found");
+    input.value = query;
+    input.dispatchEvent(new Event("input", { bubbles: true }));
+    await settle();
+    // useDataGridSearch 防抖 150ms，等待 deferredSearchText 生效
+    await new Promise((resolve) => setTimeout(resolve, 400));
+  }
+
+  it("marks the search overlay when truncated large values may hide matches (issue #7279)", async () => {
+    const { host } = mountGrid(largeValueResult(1, "preview"));
+    await openGridSearchAndType(host, "prev");
+    expect(host.querySelector("[data-grid-search-truncated-hint]")).toBeTruthy();
+  });
+
+  it("does not show the truncation hint for fully loaded values", async () => {
+    const { host } = mountGrid(hydratedResult(1, "preview"));
+    await openGridSearchAndType(host, "prev");
+    expect(host.querySelector("[data-grid-search-truncated-hint]")).toBeNull();
+  });
+
   it("offers toolbar-equivalent refresh in the cell context menu (issue #7273)", async () => {
     const onReload = vi.fn();
     const { host } = mountGrid(hydratedResult(1, "value"), onReload);
diff --git a/apps/desktop/src/i18n/locales/en.ts b/apps/desktop/src/i18n/locales/en.ts
index 472e659c7f..122f54f7a6 100644
--- a/apps/desktop/src/i18n/locales/en.ts
+++ b/apps/desktop/src/i18n/locales/en.ts
@@ -1847,6 +1847,7 @@ export default {
     batchAppendPasteEmpty: "The clipboard does not contain rows to add.",
     batchAppendPasteReadonlyColumn: "The pasted data includes a column that cannot be edited.",
     search: "Search...",
+    searchTruncatedValuesHint: "Some long text/JSON values are truncated for display; the search only covers loaded cell text and may miss matches.",
     searchOrWhere: "Search, or enter a WHERE clause...",
     applyWhere: "Apply WHERE",
     filterRows: "Filter rows",
diff --git a/apps/desktop/src/i18n/locales/es.ts b/apps/desktop/src/i18n/locales/es.ts
index a1e34ec653..2e025ca516 100644
--- a/apps/desktop/src/i18n/locales/es.ts
+++ b/apps/desktop/src/i18n/locales/es.ts
@@ -1714,6 +1714,7 @@ export default withEnglishFallback({
     unfreezeColumns: "Desinmovilizar columnas",
     pasted: "¡Pegado!",
     search: "Buscar...",
+    searchTruncatedValuesHint: "Algunos valores largos de texto/JSON están truncados para su visualización; la búsqueda solo cubre el contenido cargado y puede encontrar menos coincidencias que la consulta SQL.",
     searchOrWhere: "Buscar, o ingresar una cláusula WHERE...",
     applyWhere: "Aplicar WHERE",
     filterRows: "Filtrar filas",
diff --git a/apps/desktop/src/i18n/locales/it.ts b/apps/desktop/src/i18n/locales/it.ts
index 2df7bab821..344c6734fd 100644
--- a/apps/desktop/src/i18n/locales/it.ts
+++ b/apps/desktop/src/i18n/locales/it.ts
@@ -1712,6 +1712,7 @@ export default withEnglishFallback({
     unfreezeColumns: "Sblocca colonne",
     pasted: "Incollato!",
     search: "Cerca...",
+    searchTruncatedValuesHint: "Alcuni valori di testo/JSON lunghi sono troncati per la visualizzazione; la ricerca copre solo il contenuto caricato e può trovare meno corrispondenze della query SQL.",
     searchOrWhere: "Cerca o inserisci una clausola WHERE...",
     applyWhere: "Applica WHERE",
     filterRows: "Filtra righe",
diff --git a/apps/desktop/src/i18n/locales/ja.ts b/apps/desktop/src/i18n/locales/ja.ts
index ace333e12e..61af10ba17 100644
--- a/apps/desktop/src/i18n/locales/ja.ts
+++ b/apps/desktop/src/i18n/locales/ja.ts
@@ -1730,6 +1730,7 @@ export default withEnglishFallback({
     unfreezeColumns: "列の固定を解除",
     pasted: "貼り付けました！",
     search: "検索...",
+    searchTruncatedValuesHint: "一部の長いテキスト/JSON 値は表示用に切り詰められています。検索は読み込み済みの表示内容のみが対象で、SQL クエリより一致数が少なくなることがあります。",
     searchOrWhere: "検索、またはWHERE句を入力...",
     applyWhere: "WHEREを適用",
     filterRows: "行をフィルター",
diff --git a/apps/desktop/src/i18n/locales/ko.ts b/apps/desktop/src/i18n/locales/ko.ts
index 2c5a62fe76..3323e4e7b8 100644
--- a/apps/desktop/src/i18n/locales/ko.ts
+++ b/apps/desktop/src/i18n/locales/ko.ts
@@ -1695,6 +1695,7 @@ export default withEnglishFallback({
     unfreezeColumns: "컬럼 고정 해제",
     pasted: "붙여넣었습니다!",
     search: "검색...",
+    searchTruncatedValuesHint: "일부 긴 텍스트/JSON 값은 표시를 위해 잘렸습니다. 검색은 로드된 표시 내용만 대상으로 하며 SQL 쿼리보다 일치 수가 적을 수 있습니다.",
     searchOrWhere: "검색 또는 WHERE 절 입력...",
     applyWhere: "WHERE 적용",
     filterRows: "행 필터",
diff --git a/apps/desktop/src/i18n/locales/pt-BR.ts b/apps/desktop/src/i18n/locales/pt-BR.ts
index ea0587bdd3..2efd2c283c 100644
--- a/apps/desktop/src/i18n/locales/pt-BR.ts
+++ b/apps/desktop/src/i18n/locales/pt-BR.ts
@@ -1714,6 +1714,7 @@ export default withEnglishFallback({
     unfreezeColumns: "Descongelar colunas",
     pasted: "Colado!",
     search: "Pesquisar...",
+    searchTruncatedValuesHint: "Alguns valores longos de texto/JSON estão truncados para exibição; a busca cobre apenas o conteúdo carregado e pode encontrar menos correspondências que a consulta SQL.",
     searchOrWhere: "Pesquise, ou insira uma cláusula WHERE...",
     applyWhere: "Aplicar WHERE",
     filterRows: "Filtrar linhas",
diff --git a/apps/desktop/src/i18n/locales/zh-CN.ts b/apps/desktop/src/i18n/locales/zh-CN.ts
index 95a22112e3..6a523996d7 100644
--- a/apps/desktop/src/i18n/locales/zh-CN.ts
+++ b/apps/desktop/src/i18n/locales/zh-CN.ts
@@ -1772,6 +1772,7 @@ export default withEnglishFallback({
     batchAppendPasteEmpty: "剪贴板中没有可新增的行。",
     batchAppendPasteReadonlyColumn: "粘贴的数据包含不可编辑的列。",
     search: "搜索...",
+    searchTruncatedValuesHint: "部分长文本/JSON 值已截断显示，搜索仅覆盖已加载的显示内容，匹配数可能少于 SQL 查询。",
     searchOrWhere: "搜索，或输入 WHERE 条件...",
     applyWhere: "应用 WHERE",
     filterRows: "筛选行",
diff --git a/apps/desktop/src/i18n/locales/zh-TW.ts b/apps/desktop/src/i18n/locales/zh-TW.ts
index 0762f06c1a..e850628958 100644
--- a/apps/desktop/src/i18n/locales/zh-TW.ts
+++ b/apps/desktop/src/i18n/locales/zh-TW.ts
@@ -1713,6 +1713,7 @@ export default withEnglishFallback({
     unfreezeColumns: "取消凍結",
     pasted: "已貼上！",
     search: "搜尋……",
+    searchTruncatedValuesHint: "部分長文字/JSON 值已截斷顯示，搜尋僅涵蓋已載入的顯示內容，符合數可能少於 SQL 查詢。",
     searchOrWhere: "搜尋，或輸入 WHERE 條件……",
     applyWhere: "套用 WHERE",
     filterRows: "篩選列",