docs/docs/en/data-sources/data-modeling/collection-fields/advanced/china-region.md
<PluginInfo name="field-china-region"></PluginInfo>
In NocoBase, China region stores Chinese administrative-division information such as provinces, cities, and districts.
The China region field uses the built-in chinaRegions administrative-division collection and a cascading selector for data entry. Users select province, city, and district in order; values display as a complete hierarchical path.
For street and building-number information, use Input or Textarea.
China region is suitable for these business scenarios:
On the collection's Configure fields page, click Add field and select China region.
| Setting | Description |
|---|---|
| Field interface | China region uses chinaRegion, which determines how the field is entered and displayed. |
| Field display name | Use a business-friendly name such as Region, Service area, or Shipping region. |
| Field name | The internal identifier used by APIs, relation fields, permissions, and workflows. It supports only letters, numbers, and underscores, and must begin with a letter. |
| Field type | China region is normally stored as a related record or structured value, depending on field configuration. |
| Selection level | Controls the deepest selectable level. Province, City, and District are supported; the default is District. |
| Require the last level | When enabled, users must select the configured deepest level before submitting. Otherwise, they can complete selection at an intermediate level. |
| Validation rules | Configure required validation and selection level as needed. |
| Description | Record the field meaning, entry requirements, data source, or maintainer. |
:::warning Note
Field names are referenced by page blocks, permissions, workflows, and APIs after creation. Confirm the name before creating the field to avoid later configuration changes.
:::
| Behavior | Description |
|---|---|
| Default Field interface | chinaRegion. |
| Data source | The built-in chinaRegions administrative-division collection. |
| Page component | Uses a cascading selector in edit mode. |
| Selection levels | Supports Province, City, and District. |
| Display | Displays a Province / City / District path in read mode. |
| Filtering | Supports filtering by saved region values; capabilities depend on field configuration and blocks. |
| Multiple selection | Not supported. |
Click Edit beside the field to change its display name, description, validation rules, selection level, and whether the last level is required.
For a field from a synchronized main-database table, editing usually maps the database field to a NocoBase Field type and Field interface.
| Setting | Can be edited | Description |
|---|---|---|
| Field display name | Yes | Changes the name displayed in the interface without changing the field identifier. |
| Field name | No | The identifier normally cannot be changed after creation. |
| Field interface | Conditional | Main-database and synchronized fields can be adjusted during mapping. |
| Field type | Conditional | Confirm that existing values are compatible before changing it. |
| Selection level | Yes | Changes the selectable deepest level to Province, City, or District. |
| Require the last level | Yes | Controls whether the configured deepest level must be selected before submission. |
| Validation rules | Yes | Adjusts required and other validation. |
| Description | Yes | Adds maintenance information for the field. |
:::warning Note
China region depends on the plugin-provided chinaRegions collection. Enable the China region field plugin before using it.
:::
Click Delete beside a China region field to delete it. You can also select multiple fields and delete them in the main data source.
Deleting a China region field created in the main database usually also deletes the actual database column and its values. For a synchronized or external-data-source field, the impact depends on the data source and field origin.
:::danger Warning
Deleting a field can affect page blocks, forms, filters, permissions, workflows, APIs, imports and exports, and existing data. Confirm that the field is no longer referenced before deleting it.
:::
China region fields are suitable for addresses, regions, and statistical scenarios.
| Scenario | Use |
|---|---|
| Form block | Select province, city, and district with a cascading selector. |
| Details block | Display an administrative-division path. |
| Table block | Display the region of a record. |
| Filter block | Filter records by region. |
| Chart block | Aggregate business data by province, city, or district. |
China region uses a cascading selector in edit mode.
China region displays as a text path in read mode, for example:
Beijing / Municipal district / Dongcheng District