# Previewing Data

## Content

The **Data** tab provides a read-only preview of the current table data.
It reflects the active table configuration and allows you to verify structural and visual settings before binding the table to a runtime component.
![image](https://cdn.mescius.io/document-site-files/images/b2223940-43c2-44cf-8eda-f5ab9acd84f0/image-20260410.9e5183.png?width=800)

## What the Preview Reflects

The Data preview behaves similarly to a TableSheet view in terms of rendering:

* Column headers
* Row index
* Data values
* Column styles
* Calculated columns
* Column visibility settings
* Header indicators (such as Primary Key, Required, Read Only, and Relationship)

This allows you to confirm that schema and column configurations are applied as expected.

## Read-Only Behavior

Data cannot be edited directly in this view.
All structural changes must be made in the **Table** or **Columns** tabs.
The **Data** tab is intended for inspection and validation only.

## Relationship and Hierarchy Limitations

* Relationship columns are not expanded or navigable in this view.
* Hierarchical interaction and advanced runtime behaviors are not provided.
* Features that depend on runtime data binding are not available.

The preview only indicates that such configurations exist.

## Purpose of the Data Tab

The Data tab serves as a configuration verification layer.
For full runtime interaction—including editing, relationship traversal, and advanced hierarchical behavior—bind the table to a supported SpreadJS component such as TableSheet or GanttSheet.