diff --git a/apps/desktop/src/lib/dataGrid/dataGridCopyExtractor.ts b/apps/desktop/src/lib/dataGrid/dataGridCopyExtractor.ts
index c9cf899d57..f976c48e61 100644
--- a/apps/desktop/src/lib/dataGrid/dataGridCopyExtractor.ts
+++ b/apps/desktop/src/lib/dataGrid/dataGridCopyExtractor.ts
@@ -29,6 +29,7 @@ export const DATA_GRID_DEFAULT_COPY_PREFERENCES: readonly DataGridCopyPreference
 ];
 
 export const DATA_GRID_EXTRACTOR_CONTRACT_VERSION = 1 as const;
+export const DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION = 1 as const;
 
 export const DATA_GRID_COPY_EXTRACTOR_DESCRIPTORS: Record<DataGridCopyExtractorId, { category: DataGridExtractorCategory; separatorBefore?: boolean }> = {
   raw: { category: "raw" },
diff --git a/apps/desktop/src/stores/__tests__/settingsStore.spec.ts b/apps/desktop/src/stores/__tests__/settingsStore.spec.ts
index 807dc5efb8..e13d894f5b 100644
--- a/apps/desktop/src/stores/__tests__/settingsStore.spec.ts
+++ b/apps/desktop/src/stores/__tests__/settingsStore.spec.ts
@@ -15,6 +15,7 @@ import {
   transitionRightSidebarPanels,
 } from "@/stores/settingsStore";
 import type { AiConfigItem } from "@/types/ai";
+import { DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION } from "@/lib/dataGrid/dataGridCopyExtractor";
 
 describe("normalizeEditorSettings", () => {
   it("keeps automatic DDL refresh disabled unless explicitly enabled", () => {
@@ -332,6 +333,24 @@ describe("normalizeEditorSettings", () => {
     expect(configured.json.pretty).toBe(false);
   });
 
+  it("migrates the legacy NULL clipboard sentinel once", () => {
+    const legacy = normalizeEditorSettings({
+      dataGridExtractorOptions: {
+        dsv: { ...DEFAULT_EDITOR_SETTINGS.dataGridExtractorOptions.dsv, nullText: "NULL" },
+      },
+    });
+    expect(legacy.dataGridExtractorOptions.dsv.nullText).toBe("");
+    expect(legacy.dataGridExtractorOptionsMigrationVersion).toBe(DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION);
+
+    const configured = normalizeEditorSettings({
+      dataGridExtractorOptionsMigrationVersion: DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION,
+      dataGridExtractorOptions: {
+        dsv: { ...DEFAULT_EDITOR_SETTINGS.dataGridExtractorOptions.dsv, nullText: "NULL" },
+      },
+    });
+    expect(configured.dataGridExtractorOptions.dsv.nullText).toBe("NULL");
+  });
+
   it("defaults retained result runs to tiled tabs and preserves list mode", () => {
     expect(normalizeEditorSettings({}).resultRunDisplayMode).toBe("tabs");
     expect(normalizeEditorSettings({ resultRunDisplayMode: "list" }).resultRunDisplayMode).toBe("list");
diff --git a/apps/desktop/src/stores/settingsStore.ts b/apps/desktop/src/stores/settingsStore.ts
index 6d554806eb..595dabfb70 100644
--- a/apps/desktop/src/stores/settingsStore.ts
+++ b/apps/desktop/src/stores/settingsStore.ts
@@ -7,7 +7,7 @@ import * as api from "@/lib/backend/api";
 import { setDebugLoggingEnabled } from "@/lib/backend/debugLog";
 import { safeLocalStorageGet, safeLocalStorageRemove } from "@/lib/backend/safeStorage";
 import { type ColumnFormatterConfig, type CustomColumnFormatterConfig, normalizeColumnFormatter, normalizeCustomColumnFormatter, normalizeGlobalDateTimePattern } from "@/lib/dataGrid/columnFormatter";
-import { type DataGridCopyPreference, type DataGridExtractorOptions, DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS, normalizeDataGridCopyPreference, normalizeDataGridExtractorOptions } from "@/lib/dataGrid/dataGridCopyExtractor";
+import { type DataGridCopyPreference, type DataGridExtractorOptions, DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION, DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS, normalizeDataGridCopyPreference, normalizeDataGridExtractorOptions } from "@/lib/dataGrid/dataGridCopyExtractor";
 import { DATA_GRID_TEXT_FILTER_PANEL_HEIGHT_DEFAULT, normalizeDataGridTextFilterPanelHeight } from "@/lib/dataGrid/dataGridTextFilterPanel";
 import { DATA_GRID_TYPE_COLOR_SCHEME_AUTO_ID, type DataGridTypeColorScheme, normalizeActiveDataGridTypeColorSchemeId, normalizeDataGridTypeColorSchemes } from "@/lib/dataGrid/dataGridTypeColorScheme";
 import { normalizeResultPageSize } from "@/lib/dataGrid/paginationPageSize";
@@ -793,6 +793,7 @@ export interface EditorSettings {
   dataGridSearchMode: DataGridSearchMode;
   dataGridCopyExtractor: DataGridCopyPreference;
   dataGridExtractorOptions: DataGridExtractorOptions;
+  dataGridExtractorOptionsMigrationVersion: number;
   resultRunDisplayMode: ResultRunDisplayMode;
   multiStatementDefaultView: MultiStatementDefaultView;
   dataGridAutoTransposeSingleRow: boolean;
@@ -1027,6 +1028,7 @@ export const DEFAULT_EDITOR_SETTINGS: EditorSettings = {
   dataGridSearchMode: "filter",
   dataGridCopyExtractor: "smart",
   dataGridExtractorOptions: normalizeDataGridExtractorOptions(DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS),
+  dataGridExtractorOptionsMigrationVersion: DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION,
   resultRunDisplayMode: "tabs",
   multiStatementDefaultView: "result",
   dataGridAutoTransposeSingleRow: false,
@@ -1369,6 +1371,10 @@ export function normalizeEditorSettings(settings: Partial<EditorSettings>, exist
   const hasCurrentExecuteModeDefault = executeModeDefaultVersion === savedExecuteModeDefaultVersion;
   // The active id can only be validated once the scheme list it points into is known.
   const dataGridTypeColorSchemes = normalizeDataGridTypeColorSchemes(settings.dataGridTypeColorSchemes);
+  const savedExtractorMigrationVersion = settings.dataGridExtractorOptionsMigrationVersion;
+  const normalizedExtractorOptions = normalizeDataGridExtractorOptions(settings.dataGridExtractorOptions);
+  const isLegacyExtractorOptions = typeof savedExtractorMigrationVersion !== "number" || savedExtractorMigrationVersion < DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION;
+  const dataGridExtractorOptions = isLegacyExtractorOptions && normalizedExtractorOptions.dsv.nullText === "NULL" ? { ...normalizedExtractorOptions, dsv: { ...normalizedExtractorOptions.dsv, nullText: "" } } : normalizedExtractorOptions;
   return {
     fontFamily: normalizeFontFamily(settings.fontFamily, DEFAULT_EDITOR_SETTINGS.fontFamily),
     fontSize: settings.fontSize ?? DEFAULT_EDITOR_SETTINGS.fontSize,
@@ -1475,7 +1481,8 @@ export function normalizeEditorSettings(settings: Partial<EditorSettings>, exist
     dataGridRenderMode: normalizeDataGridRenderMode(settings.dataGridRenderMode),
     dataGridSearchMode: normalizeDataGridSearchMode(settings.dataGridSearchMode),
     dataGridCopyExtractor: normalizeDataGridCopyPreference(settings.dataGridCopyExtractor),
-    dataGridExtractorOptions: normalizeDataGridExtractorOptions(settings.dataGridExtractorOptions),
+    dataGridExtractorOptions,
+    dataGridExtractorOptionsMigrationVersion: DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION,
     resultRunDisplayMode: normalizeResultRunDisplayMode(settings.resultRunDisplayMode),
     multiStatementDefaultView: normalizeMultiStatementDefaultView(settings.multiStatementDefaultView),
     dataGridAutoTransposeSingleRow: settings.dataGridAutoTransposeSingleRow === true,
@@ -1757,8 +1764,10 @@ export const useSettingsStore = defineStore("settings", () => {
           editorSettings.value = normalized;
           const needsExecuteModeDefaultMigration = typeof savedSettings.executeModeDefaultVersion !== "number" || savedSettings.executeModeDefaultVersion < EXECUTE_MODE_CURRENT_DEFAULT_VERSION;
           const needsTabNavigationShortcutMigration = needsTabNavigationHistoryShortcutMigration(savedSettings.shortcuts);
+          const savedNullText = (savedSettings.dataGridExtractorOptions as Partial<DataGridExtractorOptions> | undefined)?.dsv?.nullText;
+          const needsDataGridExtractorOptionsMigration = (typeof savedSettings.dataGridExtractorOptionsMigrationVersion !== "number" || savedSettings.dataGridExtractorOptionsMigrationVersion < DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION) && savedNullText === "NULL";
           const savedUpdateDownloadSource = (saved as { updateDownloadSource?: unknown }).updateDownloadSource;
-          if (savedUpdateDownloadSource === "atomgit" || needsExecuteModeDefaultMigration || needsTabNavigationShortcutMigration || needsSidebarBrowseObjectsMigration) {
+          if (savedUpdateDownloadSource === "atomgit" || needsExecuteModeDefaultMigration || needsTabNavigationShortcutMigration || needsSidebarBrowseObjectsMigration || needsDataGridExtractorOptionsMigration) {
             // Persist one-time migrations so removed or unsafe defaults cannot reappear.
             await enqueueEditorSettingsSave().catch(() => {});
           }
@@ -2207,6 +2216,7 @@ export const useSettingsStore = defineStore("settings", () => {
     if (partial.dataGridSearchMode !== undefined) editorSettings.value.dataGridSearchMode = normalizeDataGridSearchMode(partial.dataGridSearchMode);
     if (partial.dataGridCopyExtractor !== undefined) editorSettings.value.dataGridCopyExtractor = normalizeDataGridCopyPreference(partial.dataGridCopyExtractor);
     if (partial.dataGridExtractorOptions !== undefined) editorSettings.value.dataGridExtractorOptions = normalizeDataGridExtractorOptions(partial.dataGridExtractorOptions);
+    if (partial.dataGridExtractorOptionsMigrationVersion !== undefined) editorSettings.value.dataGridExtractorOptionsMigrationVersion = DATA_GRID_EXTRACTOR_OPTIONS_MIGRATION_VERSION;
     if (partial.resultRunDisplayMode !== undefined) editorSettings.value.resultRunDisplayMode = normalizeResultRunDisplayMode(partial.resultRunDisplayMode);
     if (partial.multiStatementDefaultView !== undefined) editorSettings.value.multiStatementDefaultView = normalizeMultiStatementDefaultView(partial.multiStatementDefaultView);
     if (partial.dataGridAutoTransposeSingleRow !== undefined) editorSettings.value.dataGridAutoTransposeSingleRow = partial.dataGridAutoTransposeSingleRow === true;