diff --git a/apps/desktop/src/composables/__tests__/useSidebarDataOpenRuntime.spec.ts b/apps/desktop/src/composables/__tests__/useSidebarDataOpenRuntime.spec.ts
index ea0f70abf..4195781b8 100644
--- a/apps/desktop/src/composables/__tests__/useSidebarDataOpenRuntime.spec.ts
+++ b/apps/desktop/src/composables/__tests__/useSidebarDataOpenRuntime.spec.ts
@@ -11,6 +11,7 @@ const mocks = vi.hoisted(() => ({
   ensureConnected: vi.fn(),
   executeTabSql: vi.fn(),
   loadTableMetadata: vi.fn(),
+  buildTableSelectSql: vi.fn(),
   setErrorResult: vi.fn(),
   cancelTabExecution: vi.fn(),
 }));
@@ -81,7 +82,7 @@ vi.mock("@/stores/settingsStore", () => ({
 vi.mock("@/lib/database/jdbcDialect", () => ({
   effectiveDatabaseTypeForConnection: () => mocks.databaseType,
   connectionObjectTreeNodeSchema: (_config: unknown, _database: string, schema?: string) => schema,
-  connectionObjectTreeQuerySchema: (_config: unknown, _database: string, schema?: string) => schema ?? "",
+  connectionObjectTreeQuerySchema: (_config: unknown, database: string, schema?: string) => schema ?? database,
 }));
 
 vi.mock("@/lib/metadata/tableMetadataCache", async (importOriginal) => {
@@ -97,7 +98,7 @@ vi.mock("@/lib/common/utils", () => ({ uuid: () => "open-data-id" }));
 vi.mock("@/lib/backend/debugLog", () => ({ appendDebugLog: vi.fn(), isDebugLoggingEnabled: () => false }));
 // dataTabOpenPolicy 使用真实实现，覆盖设置开关对应的复用范围
 vi.mock("@/lib/sidebar/treeNodeContext", () => ({ hasTreeNodeDatabaseContext: () => true }));
-vi.mock("@/lib/table/tableSelectSql", () => ({ buildTableSelectSql: async () => "SELECT * FROM users" }));
+vi.mock("@/lib/table/tableSelectSql", () => ({ buildTableSelectSql: mocks.buildTableSelectSql }));
 vi.mock("@/lib/table/tableEditing", () => ({ usesSyntheticRowIdKey: () => false }));
 vi.mock("@/lib/table/tableOpenPageLimit", () => ({ tableOpenPageLimit: () => 100 }));
 vi.mock("@/lib/tabs/dataTabActivation", () => ({ canActivateExistingDataTableTab: () => false }));
@@ -112,6 +113,14 @@ const tableNode: TreeNode = {
   tableType: "TABLE",
 };
 
+const mysqlTableNode: TreeNode = {
+  ...tableNode,
+  id: "table-zcyy-write-off-record",
+  label: "zcyy_write_off_record",
+  database: "yf_db",
+  schema: undefined,
+};
+
 describe("useSidebarDataOpenRuntime", () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -121,6 +130,7 @@ describe("useSidebarDataOpenRuntime", () => {
     mocks.cachedMetadata = undefined;
     mocks.reuseDataTab = false;
     mocks.ensureConnected.mockResolvedValue(undefined);
+    mocks.buildTableSelectSql.mockResolvedValue("SELECT * FROM users");
     mocks.executeTabSql.mockImplementation(async () => {
       mocks.callOrder.push("query");
     });
@@ -188,6 +198,55 @@ describe("useSidebarDataOpenRuntime", () => {
     });
   });
 
+  it("keeps MySQL data-tab identity unqualified after metadata loads", async () => {
+    mocks.databaseType = "mysql";
+    mocks.loadTableMetadata.mockImplementation(async (request: { database: string; schema?: string; tableName: string; tableType?: string }) => ({
+      metadata: {
+        schema: request.schema,
+        tableName: request.tableName,
+        tableType: request.tableType,
+        database: request.database,
+        columns: [{ name: "id", data_type: "bigint", is_nullable: false, column_default: null, is_primary_key: true, extra: null }],
+        indexes: [],
+        primaryKeys: ["id"],
+        cachedAt: Date.now(),
+      },
+      cacheStatus: "miss",
+      ageMs: 0,
+    }));
+
+    await useSidebarDataOpenRuntime().openData(mysqlTableNode);
+
+    await vi.waitFor(() => expect(mocks.tabs[0]?.tableMeta?.primaryKeys).toEqual(["id"]));
+    expect(mocks.loadTableMetadata).toHaveBeenCalledWith(expect.objectContaining({ database: "yf_db", schema: "yf_db" }));
+    expect(mocks.buildTableSelectSql).toHaveBeenCalledWith(expect.objectContaining({ database: "yf_db", schema: undefined, tableName: "zcyy_write_off_record" }));
+    expect(mocks.tabs[0]?.tableMeta).toMatchObject({ database: "yf_db", schema: undefined, tableName: "zcyy_write_off_record" });
+  });
+
+  it("keeps cached MySQL table metadata unqualified", async () => {
+    mocks.databaseType = "mysql";
+    mocks.cachedMetadata = {
+      metadata: {
+        schema: "yf_db",
+        tableName: "zcyy_write_off_record",
+        tableType: "TABLE",
+        database: "yf_db",
+        columns: [{ name: "id", data_type: "bigint", is_nullable: false, column_default: null, is_primary_key: true, extra: null }],
+        indexes: [],
+        primaryKeys: ["id"],
+        cachedAt: Date.now(),
+      },
+      cacheStatus: "hit",
+      ageMs: 0,
+    };
+
+    await useSidebarDataOpenRuntime().openData(mysqlTableNode);
+
+    expect(mocks.loadTableMetadata).not.toHaveBeenCalled();
+    expect(mocks.buildTableSelectSql).toHaveBeenCalledWith(expect.objectContaining({ database: "yf_db", schema: undefined, tableName: "zcyy_write_off_record" }));
+    expect(mocks.tabs[0]?.tableMeta).toMatchObject({ database: "yf_db", schema: undefined, tableName: "zcyy_write_off_record" });
+  });
+
   it("keeps row identity pending while delayed metadata is in flight and the query finishes first", async () => {
     // 元数据延迟：查询先返回，元数据仍挂起
     let releaseMetadata: () => void = () => {};
diff --git a/apps/desktop/src/composables/useSidebarDataOpenRuntime.ts b/apps/desktop/src/composables/useSidebarDataOpenRuntime.ts
index cebde0a41..8c2aaad15 100644
--- a/apps/desktop/src/composables/useSidebarDataOpenRuntime.ts
+++ b/apps/desktop/src/composables/useSidebarDataOpenRuntime.ts
@@ -108,7 +108,7 @@ export function useSidebarDataOpenRuntime() {
           });
           return;
         }
-        const nextTableMeta = tableMetadataToDataTabMeta(loadedMetadata.metadata, tableSchema);
+        const nextTableMeta = tableMetadataToDataTabMeta(loadedMetadata.metadata, { schema: tableSchema });
         queryStore.setTableMeta(targetTabId, nextTableMeta);
         openDataLog("info", "metadata:done", {
           traceId,
@@ -223,7 +223,7 @@ export function useSidebarDataOpenRuntime() {
     // 空列的共享缓存条目不算暖缓存：columns=[] 无法区分"表确实无列"与
     // 占位/异常态，按暖缓存跳过 pending 与刷新会让整行 WHERE 保存路径
     // 在行标识未知时重新可用（#3727 审查意见）
-    const cachedTableMeta = sharedCachedTableMeta?.metadata.columns.length ? tableMetadataToDataTabMeta(sharedCachedTableMeta.metadata, tableSchema) : tabCachedTableMeta;
+    const cachedTableMeta = sharedCachedTableMeta?.metadata.columns.length ? tableMetadataToDataTabMeta(sharedCachedTableMeta.metadata, { schema: tableSchema }) : tabCachedTableMeta;
     const cachedTableMetaAgeMs = sharedCachedTableMeta?.metadata.columns.length ? sharedCachedTableMeta.ageMs : existingTableMetaAgeMs;
     const cachedTableMetaSource = sharedCachedTableMeta?.metadata.columns.length ? "shared" : tabCachedTableMeta ? "tab" : undefined;
     queryStore.setTableMeta(
diff --git a/apps/desktop/src/lib/metadata/tableMetadataCache.ts b/apps/desktop/src/lib/metadata/tableMetadataCache.ts
index df4cbdce1..c052d4518 100644
--- a/apps/desktop/src/lib/metadata/tableMetadataCache.ts
+++ b/apps/desktop/src/lib/metadata/tableMetadataCache.ts
@@ -103,9 +103,9 @@ export function getCachedTableMetadata(request: Pick<TableMetadataRequest, "conn
   return { metadata: hit.value, cacheStatus: hit.stale ? "stale" : "hit", ageMs: hit.ageMs };
 }
 
-export function tableMetadataToDataTabMeta(metadata: TableMetadata, schema = metadata.schema): NonNullable<QueryTab["tableMeta"]> {
+export function tableMetadataToDataTabMeta(metadata: TableMetadata, overrides?: { schema?: string }): NonNullable<QueryTab["tableMeta"]> {
   return {
-    schema,
+    schema: overrides ? overrides.schema : metadata.schema,
     tableName: metadata.tableName,
     tableType: metadata.tableType,
     catalog: metadata.catalog,
diff --git a/apps/desktop/src/stores/__tests__/queryStore.tableDataRefresh.spec.ts b/apps/desktop/src/stores/__tests__/queryStore.tableDataRefresh.spec.ts
index ecfbe5f8a..407b4854e 100644
--- a/apps/desktop/src/stores/__tests__/queryStore.tableDataRefresh.spec.ts
+++ b/apps/desktop/src/stores/__tests__/queryStore.tableDataRefresh.spec.ts
@@ -166,6 +166,33 @@ describe("queryStore table data refresh", () => {
     expect(store.tabs.find((tab) => tab.id === secondTabId)?.result).toBeUndefined();
   });
 
+  it("keeps a MySQL table refresh unqualified in the selected database context", async () => {
+    mocks.getConnectionConfig.mockReturnValue({
+      id: "mysql-1",
+      name: "MySQL Proxy",
+      db_type: "mysql",
+      database: "yf_db",
+      query_timeout_secs: 30,
+    });
+    mocks.buildTableSelectSql.mockResolvedValue("SELECT * FROM `zcyy_write_off_record` LIMIT 100;");
+    const { useQueryStore } = await import("@/stores/queryStore");
+    const store = useQueryStore();
+    const tabId = store.createTab("mysql-1", "yf_db", "zcyy_write_off_record", "data");
+    store.setTableMeta(tabId, {
+      database: "yf_db",
+      schema: undefined,
+      tableName: "zcyy_write_off_record",
+      tableType: "TABLE",
+      columns: [{ name: "id", data_type: "bigint", is_nullable: false, column_default: null, is_primary_key: true, extra: null }],
+      primaryKeys: ["id"],
+    });
+
+    await expect(store.refreshDataTab(tabId)).resolves.toBe(true);
+
+    expect(mocks.buildTableSelectSql).toHaveBeenCalledWith(expect.objectContaining({ databaseType: "mysql", database: "yf_db", schema: undefined, tableName: "zcyy_write_off_record" }));
+    expect(store.tabs.find((tab) => tab.id === tabId)?.sql).toBe("SELECT * FROM `zcyy_write_off_record` LIMIT 100;");
+  });
+
   it("clears a structured sort when refreshed table metadata no longer contains its column", async () => {
     const { useQueryStore } = await import("@/stores/queryStore");
     const store = useQueryStore();