---
title: Table Structure Editor
description: Edit table columns and indexes visually, then preview DDL before applying changes.
---

The table structure editor modifies columns, indexes, and some constraints for a single table. Use it for focused structure changes or to generate reviewable DDL without writing it by hand.

## What You Can Edit

| Object | Supported Actions |
|---|---|
| Columns | Add and delete columns; MySQL/PostgreSQL can modify existing columns, and SQLite can rename columns |
| Indexes | Add indexes and delete existing non-primary indexes |
| Comments | MySQL/PostgreSQL can write column comments; PostgreSQL can write index comments |

Database engines differ in DDL capabilities. DBX generates SQL for the active connection type.

## Workflow

<Steps>
  <Step>
    ### Open Table Structure

    Right-click a table in the sidebar and open its structure view.
  </Step>
  <Step>
    ### Edit Columns or Indexes

    Add, modify, or remove columns and indexes in the visual editor. Changes are staged locally first.
  </Step>
  <Step>
    ### Review SQL Preview

    Before saving, review generated statements such as `ALTER TABLE`, `CREATE INDEX`, and `DROP INDEX`.
  </Step>
  <Step>
    ### Apply Changes

    Execute the SQL only after confirming it matches your intent.
  </Step>
</Steps>

<Callout type="warn">
Dropping columns, changing column types, and changing nullable constraints can affect existing data. Back up production databases first and confirm application code does not depend on the old structure.
</Callout>

## Engine Differences

| Engine | Notes |
|---|---|
| MySQL / MariaDB | Add, delete, and modify columns; add and delete indexes |
| PostgreSQL | Rename columns, change type/default/nullability/comments, and add/delete indexes |
| SQLite | Add, delete, and rename columns; more complex existing-column edits are blocked with a warning |
| SQL Server / Oracle and others | Adding columns and indexes is available; editing existing columns is currently blocked by the editor |

## Recommendations

- Use the editor for small, focused changes
- For large migrations, generate SQL and review it in your code repository
- For environment sync, use [Schema Diff](/en/docs/schema-diff)
- When impact is uncertain, back up first with [Database Export](/en/docs/database-export)