diff --git a/apps/desktop/src/composables/__tests__/useDataGridEditor.spec.ts b/apps/desktop/src/composables/__tests__/useDataGridEditor.spec.ts
index a250a0257b..c9b8c1f4f0 100644
--- a/apps/desktop/src/composables/__tests__/useDataGridEditor.spec.ts
+++ b/apps/desktop/src/composables/__tests__/useDataGridEditor.spec.ts
@@ -36,7 +36,15 @@ vi.mock("@/stores/productionSafetyStore", () => ({
   useProductionSafetyStore: () => ({}),
 }));
 
-function createEditor(sourceColumns?: Array<string | undefined>, confirmDangerousRowDeletion = true, cacheKey?: string, readonlyColumnIndexes?: number[], existingRows: CellValue[][] = [], onCellValueChanged?: (rowId: number, columnIndex: number) => void) {
+function createEditor(
+  sourceColumns?: Array<string | undefined>,
+  confirmDangerousRowDeletion = true,
+  cacheKey?: string,
+  readonlyColumnIndexes?: number[],
+  existingRows: CellValue[][] = [],
+  onCellValueChanged?: (rowId: number, columnIndex: number) => void,
+  tableColumns?: Array<{ name: string; data_type: string; extra?: string; column_default?: string }>,
+) {
   let editor: ReturnType<typeof useDataGridEditor>;
   const result = ref<{ columns: string[]; rows: CellValue[][] }>({
     columns: ["first", "hidden", "last"],
@@ -51,7 +59,7 @@ function createEditor(sourceColumns?: Array<string | undefined>, confirmDangerou
     database: computed(() => "app"),
     tableMeta: computed(() => ({
       tableName: "people",
-      columns: [
+      columns: tableColumns ?? [
         { name: "first", data_type: "varchar" },
         { name: "hidden", data_type: "varchar" },
         { name: "last", data_type: "varchar" },
@@ -388,6 +396,29 @@ describe("useDataGridEditor appendPastedRowsToNewRow", () => {
     expect(editor.hasPendingChanges.value).toBe(true);
   });
 
+  it("clears generated key columns instead of pasting the copied value", () => {
+    const editor = createEditor(undefined, true, undefined, undefined, [], undefined, [
+      { name: "first", data_type: "integer", extra: "autoincrement" },
+      { name: "hidden", data_type: "varchar" },
+      { name: "last", data_type: "varchar" },
+    ]);
+
+    const result = editor.appendPastedRowsToNewRow(
+      -1,
+      [
+        ["1", "Lovelace"],
+        ["2", "Hopper"],
+      ],
+      [0, 2],
+    );
+
+    expect(result).toEqual({ ok: true, rowCount: 2 });
+    expect(editor.newRows.value).toEqual([
+      [null, null, "Lovelace"],
+      [null, null, "Hopper"],
+    ]);
+  });
+
   it("keeps explicitly read-only mapped columns out of editing and paste", () => {
     const editor = createEditor(["first", "hidden", "last"], true, undefined, [0]);
 
diff --git a/apps/desktop/src/composables/useDataGridEditor.ts b/apps/desktop/src/composables/useDataGridEditor.ts
index 4bfef5971e..8659a81fc9 100644
--- a/apps/desktop/src/composables/useDataGridEditor.ts
+++ b/apps/desktop/src/composables/useDataGridEditor.ts
@@ -1167,10 +1167,16 @@ export function useDataGridEditor(options: UseDataGridEditorOptions) {
         reusableNewRowCount++;
       }
     }
+    const shouldClearColumn = clonedColumnClearPredicate();
     const mappedRows = pastedRows.map((pastedRow, rowIndex) => {
       const nextRow = rowIndex < reusableNewRowCount ? nextRows[targetNewIndex! + rowIndex]! : emptyDraftRow();
       for (let columnOffset = 0; columnOffset < Math.min(pastedRow.length, targetColumns.length); columnOffset++) {
         const columnIndex = targetColumns[columnOffset]!;
+        // Pasting a copied row into a new row must not reuse its generated key.
+        if (shouldClearColumn(columnIndex)) {
+          nextRow[columnIndex] = null;
+          continue;
+        }
         const value = pastedRow[columnOffset];
         nextRow[columnIndex] = value === null ? null : coerceCellValue(value, nextRow[columnIndex], columnIndex);
       }
@@ -1205,15 +1211,26 @@ export function useDataGridEditor(options: UseDataGridEditorOptions) {
   }
 
   function clonedRowData(item: RowItem, resolvedValues?: ReadonlyMap<number, CellValue>): CellValue[] {
-    const columnInfoByName = new Map((tableMeta.value?.columns ?? []).map((column) => [column.name.toLowerCase(), column]));
+    const shouldClearColumn = clonedColumnClearPredicate();
     return item.data.map((val, i) => {
-      const columnName = sourceColumns.value?.[i] ?? result.value.columns[i];
-      const columnInfo = columnInfoByName.get(columnName.toLowerCase());
-      if (shouldClearClonedColumn(columnName, columnInfo)) return null;
+      if (shouldClearColumn(i)) return null;
       return resolvedValues?.has(i) ? (resolvedValues.get(i) ?? null) : val;
     });
   }
 
+  // Columns generated by the database (auto increment / identity / sequence
+  // defaults) must not be carried over when a row's values are copied into a
+  // new row, otherwise saving fails on a duplicate key. Both the clone-row and
+  // the clipboard-paste paths resolve the columns through this predicate.
+  function clonedColumnClearPredicate(): (columnIndex: number) => boolean {
+    const columnInfoByName = new Map((tableMeta.value?.columns ?? []).map((column) => [column.name.toLowerCase(), column]));
+    return (columnIndex: number) => {
+      const columnName = sourceColumns.value?.[columnIndex] ?? result.value.columns[columnIndex];
+      if (columnName === undefined) return false;
+      return shouldClearClonedColumn(columnName, columnInfoByName.get(columnName.toLowerCase()));
+    };
+  }
+
   function shouldClearClonedColumn(columnName: string, columnInfo: ColumnInfo | undefined): boolean {
     if (usesSyntheticRowIdKey(resolvedDatabaseType.value, [columnName])) return true;
     if (resolvedDatabaseType.value === "neo4j" && columnName === DBX_NEO4J_ELEMENT_ID_COLUMN) return true;