> ## Documentation Index
> Fetch the complete documentation index at: https://help.dingtalk.io/llms.txt
> Use this file to discover all available pages before exploring further.

# EXIST

> The EXIST function checks whether currently submitted data duplicates existing historical records. It is supported in YiDA form validation and workflow design. This function can check for duplicates across multiple component types, including Single-line text and Multi-line text, and returns a boolean value indicating whether a duplicate record exists.

The **EXIST** function checks whether currently submitted data duplicates existing historical records.

## Supported Product Scenarios

The EXIST function is supported in the following YiDA scenarios.

* Form (validation)
* Workflow design (validation rules)

<Note>
  - EXIST does not support duplicate checking for components inside a subform.
  - When EXIST performs a duplicate check, every component must have a value. If any component is empty, the system does not treat the record as a duplicate.
  - Components currently supported by EXIST: Single-line text, Multi-line text, Numerical, Select, Dropdown select, Checkbox, Dropdown checkbox, Cascading select, Date, Date range, User, Country, and Department.
</Note>

## Format

```text theme={"theme":{"light":"github-light","dark":"github-dark"}}
EXIST(value1,value2···value5)
```

## Attribute Description

| **Attribute** | **Required** | **Description**                                                                                                                                                   |
| ------------- | ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| value1        | Yes          | The component field to check.<br />Supports checking values across multiple components. Separate the components with commas. Up to five components are supported. |

## Return Value

| **Return value type** | **Description**                                                                       |
| --------------------- | ------------------------------------------------------------------------------------- |
| Boolean               | The comparison result.<br />• **true**: Duplicate.<br />• **false**: Not a duplicate. |

## Example

Use the `EXIST()` function to check whether a field value already exists, as shown below.

## Try It Out

Check whether a field value or a combined field value already exists in the database.