# Get a discovery expression by ID.

Endpoint: GET /discovery-expressions/{expressionId}
Version: 3.23.0
Security: ApiKeyAuth

## Security:

  - `ApiKeyAuth` (unknown)
    apiKey in header Authorization

## Path parameters:

  - `expressionId` (string, required)
    The ID of the discovery expression.

## Response 200:

  - `200` (unknown)
    OK

## Response 200 fields (application/json):

  - `id` (string)
    The id of the discovery expression.
    Example: 5ff0dab4-368c-4d57-8b61-9a09b6e80f42

  - `name` (string)
    The name of the discovery expression.
    Example: my expression

  - `regular_expression` (string)
    The regular expression that will be used to match against column/field names or data values during the execution of a discovery job. Only applicable for SEARCH expressions.
    Example: .*

  - `data_level_profiling` (boolean)
    This field determines whether the discovery expression will be targeted at the underlying data in a data source (e.g. row values in the database column / field values in the file), or whether the discovery expression will be targeted at the schema of the data source (e.g. column names in a database table or field names in a file). Data-Level profiling consumes more memory than Column-Name-Level/Field-Name-Level profiling due to the fact that the discovery expression must be checked against a larger number of data values (e.g. hundreds) than column/field names (i.e. one). Only applicable for SEARCH expressions.
    Example: true

  - `min_data_length` (integer)
    Minimum length of the value for string types. Only applicable for TYPE expressions.
    Example: 1

  - `engine_id` (string)
    The id of the engine associated with this discovery expression.
    Example: 5ff0dab4-368c-4d57-8b61-9a09b6e80f42

  - `engine_name` (string)
    The name of the engine associated with this discovery expression.
    Example: my engine

  - `data_class_id` (string)
    The id of the data class associated with this discovery expression.
    Example: 6b5c4d3e-2a1b-4c3d-5e6f-7a8b9c0d1e2f

  - `data_class_name` (string)
    The name of the data class associated with this discovery expression.
    Example: My Domain

  - `data_type` (string)
    Data type to apply a constraint to. Only applicable for TYPE expressions.
    Enum: "String", "Number", "Date", "Binary"

  - `expression_type` (string)
    The type of the discovery expression.
    Enum: "SEARCH", "TYPE"

  - `level` (string)
    The level of data sources this discovery expression will be targeted.
    Enum: "DATA", "COLUMN", "TYPE"

  - `tags` (array)
    The tags of this discovery expression.

  - `tags.key` (string, required)
    Key of the tag
    Example: key-1

  - `tags.value` (string, required)
    Value of the tag
    Example: value-1