# Table Structure

In Ondeva, **tables define your application's data model**. Think of them as the backbone of your backend — every form, automation, query, or dashboard ultimately connects to data that lives here.

The **Table Structure** view is where you define fields, their types, validations, and behavior. It's also where you configure table-level settings like per-user limits or identifying columns. Ondeva ensures changes are saved instantly, so structure editing is frictionless and production-safe.

### Accessing the Table Structure

To edit a table:

* Navigate to the **Data** tab from the left sidebar.
* Select a table from the list (or create a new one).
* You'll be taken directly to the **Structure** tab — the schema editor for your table.

Here, you'll define columns, choose their types, configure field properties, and manage table-level settings.

### Table Settings

Clicking on an empty space in the **Structure** view reveals general settings for the table in the right-hand panel.

#### Available Table-Level Settings

* **Table Name**\
  Editable directly from the top title bar. The name is persisted across all references (queries, workflows, API exposure).
* **One Entry Per User**\
  When enabled, this restricts each frontend user to a single entry in the table. Ideal for profiles, preferences, or single submissions.

### Working with Fields

Each table is composed of [**fields**](https://docs.ondeva.com/data/custom-tables/field-types-and-configuration) (columns).\
You can:

* Add fields with the "+" button
* Rename by clicking the label
* Reorder by drag-and-drop
* Remove fields via the trash icon

Fields can also be marked as:

* **Identifying Column**: This becomes the default display label across UI components, dropdowns, and table references.

{% hint style="info" %}
Note: Every structural change — adding fields, renaming columns, changing types — is **persisted immediately**. You can refresh or return later and all definitions will remain intact.
{% endhint %}

### Summary

The **Table Structure** area in Ondeva gives you full control over your data model with:

* Instant updates
* Developer-grade validations
* A wide range of input types
* Full support for relationships, geodata, and advanced field logic

Whether you're modeling a CRM, form backend, analytics dashboard, or a marketplace database, your table starts here.