diff --git a/packages/toolpad-app/src/toolpadDataSources/postgres/client.tsx b/packages/toolpad-app/src/toolpadDataSources/postgres/client.tsx
index 54f3a27983e..63b8efa6213 100644
--- a/packages/toolpad-app/src/toolpadDataSources/postgres/client.tsx
+++ b/packages/toolpad-app/src/toolpadDataSources/postgres/client.tsx
@@ -7,6 +7,7 @@ import { useForm } from 'react-hook-form';
 import CheckCircleOutlineIcon from '@mui/icons-material/CheckCircleOutline';
 import ErrorOutlineIcon from '@mui/icons-material/ErrorOutline';
 import SyncIcon from '@mui/icons-material/Sync';
+import { getObjectKey } from '@mui/toolpad-core/objectKey';
 import SplitPane from '../../components/SplitPane';
 import ErrorAlert from '../../toolpad/AppEditor/PageEditor/ErrorAlert';
 import ParametersEditor from '../../toolpad/AppEditor/PageEditor/ParametersEditor';
@@ -189,6 +190,7 @@ function QueryEditor({
   const rawRows: any[] = preview?.data || EMPTY_ROWS;
   const columns: GridColDef[] = React.useMemo(() => parseColumns(inferColumns(rawRows)), [rawRows]);
   const rows = React.useMemo(() => rawRows.map((row, id) => ({ id, ...row })), [rawRows]);
+  const previewGridKey = React.useMemo(() => getObjectKey(columns), [columns]);
 
   return (
     <QueryEditorShell onCommit={handleCommit} isDirty={isDirty}>
@@ -220,7 +222,7 @@ function QueryEditor({
         {preview?.error ? (
           <ErrorAlert error={preview?.error} />
         ) : (
-          <DataGridPro sx={{ border: 'none' }} columns={columns} rows={rows} />
+          <DataGridPro sx={{ border: 'none' }} columns={columns} key={previewGridKey} rows={rows} />
         )}
       </SplitPane>
     </QueryEditorShell>
diff --git a/packages/toolpad-app/tsconfig.json b/packages/toolpad-app/tsconfig.json
index 646db9a3032..3c36a973aaf 100644
--- a/packages/toolpad-app/tsconfig.json
+++ b/packages/toolpad-app/tsconfig.json
@@ -2,7 +2,8 @@
   "compilerOptions": {
     "paths": {
       // TODO: remove when we move to typescript 4.7 (supports package exports)
-      "@mui/toolpad-core/runtime": ["../toolpad-core/dist/runtime"]
+      "@mui/toolpad-core/runtime": ["../toolpad-core/dist/runtime"],
+      "@mui/toolpad-core/objectKey": ["../toolpad-core/dist/objectKey"]
     },
     "target": "es5",
     "lib": ["dom", "dom.iterable", "esnext"],
diff --git a/packages/toolpad-components/src/DataGrid.tsx b/packages/toolpad-components/src/DataGrid.tsx
index 7d1c021915a..f6bc268e521 100644
--- a/packages/toolpad-components/src/DataGrid.tsx
+++ b/packages/toolpad-components/src/DataGrid.tsx
@@ -13,10 +13,12 @@ import {
   GridSelectionModel,
   GridValueFormatterParams,
   GridColDef,
+  GridValueGetterParams,
 } from '@mui/x-data-grid-pro';
 import * as React from 'react';
 import { useNode, createComponent } from '@mui/toolpad-core';
 import { Box, debounce, LinearProgress, Skeleton, styled } from '@mui/material';
+import { getObjectKey } from '@mui/toolpad-core/objectKey';
 
 // Pseudo random number. See https://stackoverflow.com/a/47593316
 function mulberry32(a: number): () => number {
@@ -124,13 +126,19 @@ const DEFAULT_TYPES = new Set([
   'actions',
 ]);
 
+function dateValueGetter({ value }: GridValueGetterParams<any, any>) {
+  return typeof value === 'number' ? new Date(value) : value;
+}
+
 const COLUMN_TYPES: Record<string, Omit<GridColDef, 'field'>> = {
   json: {
     valueFormatter: ({ value: cellValue }: GridValueFormatterParams) => JSON.stringify(cellValue),
   },
-  datetime: {
-    valueFormatter: ({ value: cellValue }: GridValueFormatterParams) =>
-      typeof cellValue === 'number' ? new Date(cellValue) : cellValue,
+  date: {
+    valueGetter: dateValueGetter,
+  },
+  dateTime: {
+    valueGetter: dateValueGetter,
   },
 };
 
@@ -286,6 +294,13 @@ const DataGridComponent = React.forwardRef(function DataGridComponent(
 
   const columns: GridColumns = React.useMemo(() => parseColumns(columnsProp || []), [columnsProp]);
 
+  // The grid doesn't react to changes to the column prop, so it needs to be remounted
+  // when that updates to reflect changes made in the editor.
+  const key = React.useMemo(
+    () => [rowIdFieldProp ?? '', getObjectKey(columnsProp)].join('::'),
+    [columnsProp, rowIdFieldProp],
+  );
+
   return (
     <div ref={ref} style={{ height: heightProp, minHeight: '100%', width: '100%' }}>
       <DataGridPro
@@ -294,7 +309,7 @@ const DataGridComponent = React.forwardRef(function DataGridComponent(
         onColumnOrderChange={handleColumnOrderChange}
         rows={rows}
         columns={columns}
-        key={rowIdFieldProp}
+        key={key}
         getRowId={getRowId}
         onSelectionModelChange={onSelectionModelChange}
         selectionModel={selectionModel}
diff --git a/packages/toolpad-components/tsconfig.json b/packages/toolpad-components/tsconfig.json
index da5f0e92dd1..0e90c5c34c7 100644
--- a/packages/toolpad-components/tsconfig.json
+++ b/packages/toolpad-components/tsconfig.json
@@ -1,6 +1,10 @@
 {
   "extends": "../../tsconfig.json",
   "compilerOptions": {
+    "paths": {
+      // TODO: remove when we move to typescript 4.7 (supports package exports)
+      "@mui/toolpad-core/objectKey": ["../toolpad-core/dist/objectKey"]
+    },
     "module": "esnext",
     "alwaysStrict": true,
     "rootDir": "src",
diff --git a/packages/toolpad-core/package.json b/packages/toolpad-core/package.json
index 09459041c2f..cd7644ed3e6 100644
--- a/packages/toolpad-core/package.json
+++ b/packages/toolpad-core/package.json
@@ -13,6 +13,7 @@
     ".": "./dist/index.js",
     "./constants": "./dist/constants.js",
     "./runtime": "./dist/runtime.js",
+    "./objectKey": "./dist/objectKey.js",
     "./utils": "./dist/utils.js"
   },
   "files": [
diff --git a/packages/toolpad-core/src/objectKey.ts b/packages/toolpad-core/src/objectKey.ts
new file mode 100644
index 00000000000..ac113a64dbc
--- /dev/null
+++ b/packages/toolpad-core/src/objectKey.ts
@@ -0,0 +1,22 @@
+// TODO: Create a @mui/toolpad-utils package to house utilities like this one?
+
+const weakMap = new WeakMap<any, string>();
+let nextId = 0;
+
+function getNextId(): string {
+  const id = `object-id::${nextId}`;
+  nextId += 1;
+  return id;
+}
+
+/**
+ * Used to generate ids for object instances.
+ */
+export function getObjectKey(object: any): string {
+  let id = weakMap.get(object);
+  if (!id) {
+    id = getNextId();
+    weakMap.set(object, id);
+  }
+  return id;
+}