# tExtractDynamicFields

Parses a Dynamic column to create standard output columns.

## tExtractDynamicFields Standard properties

These properties are used to configure tExtractDynamicFields running in the Standard Job framework.

The Standard tExtractDynamicFields component belongs to the Processing family.

The component in this framework is available in all subscription-based Talend products.

## Basic settings

| Properties | Description |
| --- | --- |
| Schema and Edit Schema | <ul> <li> <p>A schema is a row description, it defines the number of fields to be processed                and passed on to the next component. The schema is either <span>Built-in</span> or stored remotely in the <span>Repository</span>.</p> <p>Click <span>Edit        schema</span> to make changes to the schema. If the current schema is of the <span>Repository</span> type, three options are available:</p> <ul> <li> <p> <span>View schema</span>: choose this                option to view the schema only.</p> </li> <li> <p> <span>Change to built-in property</span>:                choose this option to change the schema to <span>Built-in</span> for local changes.</p> </li> <li> <p> <span>Update repository connection</span>:                choose this option to change the schema stored in the repository and decide whether                to propagate the changes to all the Jobs upon completion.</p> <p>If you just want to                propagate the changes to the current Job, you can select <span>No</span> upon completion and choose this schema metadata                again in the <span>Repository Content</span>                window.</p> </li> </ul> <p>Click <span>Sync columns</span> to retrieve the schema from                the previous component in the Job.</p> <p>This component offers the advantage of the                  dynamic schema feature. This allows you to retrieve unknown columns from source                  files or to copy batches of columns from a source without mapping each column                  individually. For further information about dynamic schemas, see <a href="https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/dynamic-schema" target="_blank">Dynamic schema</a>.</p> <p>This            dynamic schema feature is designed for the purpose of retrieving unknown columns of a            table and is recommended to be used for this purpose only; it is not recommended for the            use of creating tables.</p> </li> <li> <p> <span>Built-in</span>: You create the schema and store it                locally for the relevant component. For more information about a component schema in its <span>Basic settings</span> tab, see <a href="https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/basic-settings-tab" target="_blank">Basic settings tab</a>.</p> </li> <li> <p> <span>Repository</span>: The schema already exists and is                stored in the Repository, hence can be reused in various projects and Job                flowcharts. For more information about a component schema in its <span>Basic settings</span> tab, see <a href="https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/basic-settings-tab" target="_blank">Basic settings tab</a>.</p> </li> </ul> |

## Advanced settings

| Properties | Description |
| --- | --- |
| tStatCatcher Statistics | Select this check box to gather the Job processing metadata at a Job level as<br>well as at each component level. |

## Global Variables

| Variables | Description |
| --- | --- |
| Global Variables | ERROR\_MESSAGE: the error message generated by the<br>component when an error occurs. This is an After variable and it returns a string. This<br>variable functions only if the Die on error checkbox is<br>cleared, if the component has this checkbox.<br><br><br>NB\_LINE: the number<br>of rows read by an input component or transferred to an output component. This is an<br>After variable and it returns an integer.<br><br>A Flow variable functions during the execution of a component<br>while an After variable functions after the execution of the component.<br><br>To fill up a field or expression with a variable, press Ctrl+Space to access the variable list and choose the variable to use from<br>it.<br><br>For more information about variables, see [Using contexts and variables](https://help.qlik.com/talend/r/en-US/8.0/studio-user-guide/contexts-and-variables). |

## Usage

| Usage guidance | Description |
| --- | --- |
| **Usage rule** | This component handles flow of data therefore it requires input and output<br>components. |

**Related concepts**

* [Creating a dynamic column and extract its content](https://help.qlik.com/talend/en-US/components/8.0/processing/twritedynamicfields-textractdynamicfields-tlogrow-trowgenerator-creating-dynamic-column-and-extract-its-content-standard-component-enterprise-this)
* [Deduplicating entries based on dynamic schema](https://help.qlik.com/talend/en-US/components/8.0/processing/deduplicating-entries-dynamic-schemas)