# Constant (ConstantGenerator)

The [Constant](https://docs.tonic.ai/app/generation/generators/generator-reference/constant) generator uses a single value to mask all of the values in the column.

## Link object structure <a href="#generator-api-constant-link-object" id="generator-api-constant-link-object"></a>

The Constant generator does not support linking or consistency. You cannot configure differential privacy.

The `metadata` object is populated from the [`ConstantMetadata`](https://app.tonic.ai/apidocs/index.html#/models/ConstantMetadata) object.

The `constant` field specifies the value to use to populate the column.

```json
{
  "schema": "string",
  "table": "string",
  "column": "estring",
  "path": "string",  //JSON fields only
  "dataType": "string",  //MongoDB, Amazon DynamoDB, and JSON fields only
  "metadata": {
    "presetId": "string",
    "generatorId": "ConstantGenerator",
    "constant": "string",
    "encryptionProcessor": "x-on", //To use configured Structural data encryption
    "customValueProcessor": "string" //If custom value processor applied
  }
}
```

## Example replacement <a href="#generator-api-constant-replacement" id="generator-api-constant-replacement"></a>

In the following example replacement, the `education-num` column value is replaced by the value `10`.

```json
{
  "name": "education-num",
  "schema": "public",
  "table": "users",
  "links": [
    {
      "schema": "public",
      "table": "users",
      "column": "education-num",
      "metadata": {
        "presetId": "ConstantGenerator",
        "generatorId": "ConstantGenerator",
        "constant": "10"
      }
    }
  ]
}
```