# Preview table data

Preview table data without modifying table content.

```text
POST $CLOUDSIGMA_API_BASE/catalog/table/preview
```

## Before you call this API

Configure the [regional API endpoint and authentication](https://omnifabric.cloudsigma.com/docs/developer/endpoints-and-authentication.html.md), and select the target workspace.

First [query the object](https://omnifabric.cloudsigma.com/docs/reference/api/ai-studio/resource-center/catalog/list-database-objects.html.md) in the database to obtain the target table ID, or prepare the table name and database positioning parameters.

Set the operation-specific values used in the request:

- `$TABLE_ID`: Table ID to preview.

## Request example

```bash
curl -X POST "$CLOUDSIGMA_API_BASE/catalog/table/preview" \
  -H "X-API-Key: $CLOUDSIGMA_API_KEY" \
  -H "X-Workspace-ID: $WORKSPACE_ID" \
  -H 'Content-Type: application/json' \
  -d '{
    "id": '"$TABLE_ID"'
  }'
```

## Request body

The positioning method of the table is consistent with [query table information](https://omnifabric.cloudsigma.com/docs/reference/api/ai-studio/resource-center/catalog/get-table.html.md): pass in `id`, or pass in `name` and `database_id`/`database_name`.

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `id` | integer | Conditionally required | Table ID. You do not need to pass the name after providing it. |
| `name` | string | Conditionally required | Table name; required if `id` is not provided. |
| `database_id` | integer | Conditionally required | Non-system database ID; mutually exclusive with `database_name`. |
| `database_name` | string | Conditionally required | System database name; mutually exclusive with `database_id`. |
| `page` | integer | No | Page number; if it is not transmitted or is less than or equal to `0`, it will be processed as page `1`. |
| `page_size` | integer | No | The number of items per page; use `100` when it is not transmitted or is less than or equal to `0`. |
| `preview_lines` | integer | No | Number of preview rows; passing a positive number overwrites `page_size` and starts at page `1`. |
| `include_total` | boolean | No | Whether to return the total number of rows; return if not transmitted. |

## Successful response

Returns `200` and preview results on success. The returned fields are consistent with [query table data](https://omnifabric.cloudsigma.com/docs/reference/api/ai-studio/resource-center/catalog/get-table-data.html.md).

```json
{
  "code": "OK",
  "msg": "OK",
  "data": {
    "data": [
      ["1", "100.00"]
    ],
    "columns": [
      {
        "name": "id",
        "type": "INT"
      },
      {
        "name": "amount",
        "type": "DECIMAL"
      }
    ],
    "page": 1,
    "page_size": 100
  }
}
```

The response fields are as follows.

| Field | Type | Description |
| --- | --- | --- |
| `code` | string | `OK` on success. |
| `msg` | string | `OK` on success. |
| `data.data` | array | Row data; each inner array is arranged in the order of `columns`. |
| `data.columns` | array | Column information, each item contains `name` and `type`. |
| `data.total_rows` | integer | Total number of table rows; only returned when `include_total` is requested. |
| `data.page` | integer | Current page number. |
| `data.page_size` | integer | The maximum number of lines per page. |

## Error response

```json
{
  "code": "ErrParamInvalid",
  "msg": "表定位参数无效",
  "data": null
}
```

### Common HTTP errors

```{list-table}
:header-rows: 1
:widths: 12 22 32 34

* - HTTP status code
  - error code
  - Common causes
  - Recommended actions
* - `400`
  - `ErrParamInvalid`
  - Invalid table ID, name positioning, or paging parameters.
  - Use the table ID, or complete the table name and database location parameters.
* - `403`
  - `ErrForbidden`
  - The current identity does not have table read permission.
  - Check workspace and table authorizations.
* - `409`
  - `ErrReadonlySystemDatabase`
  - The system database does not support the current read path.
  - Use supported table positioning methods instead.
* - `500`
  - `ErrServer`
  - The service cannot preview table data.
  - Record the request time and error message and try again; if it continues to fail, contact support.
```

## Follow-up operations

After completion, [Query Catalog details](https://omnifabric.cloudsigma.com/docs/reference/api/ai-studio/resource-center/catalog/get-catalog.html.md) confirms the result.