# Testing a regular expression in the Pattern Test View

Available in...

* Big Data Platform
* Cloud API Services Platform
* Cloud Big Data Platform
* Cloud Data Fabric
* Cloud Data Management Platform
* Data Fabric
* Data Management Platform
* Data Services Platform
* Qlik Talend Cloud Enterprise Edition
* Qlik Talend Cloud Premium Edition
* Real-Time Big Data Platform

It is possible to test character sequences against a predefined or newly created regular expression.

## Before you begin

At least one database connection is set in the Profiling perspective of Talend Studio.

## Procedure

1. Follow the steps outlined in [Creating a new regular expression or SQL pattern](https://help.qlik.com/talend/en-US/studio-user-guide/8.0/creating-new-regular-expression-or-sql-pattern) to create a new regular expression.
2. In the open pattern editor, click Pattern Definition to open the relevant view.

   ![Overview of the Pattern Definition section.](https://help.qlik.com/talend/en-US/studio-user-guide/Resources/images/Pattern_Test_View2.png)
3. Click the Test button next to the definition against which you want to test a character sequence to proceed to the next step.

   The test view is displayed in Talend Studio showing the selected regular expression.

   ![Overview of Pattern Test View.](https://help.qlik.com/talend/en-US/studio-user-guide/Resources/images/Pattern_Test_View.png)
4. In the Test Area, enter the character sequence you want to check against the regular expression
5. From the DB Connection list, select the database in which you want to use the regular expression.

   Information noteNote: If you select to test a regular expression in Java, the Java option will be selected by default and the DB Connections option and list will be unavailable in the test view.
6. Click Test.

   An icon is displayed in the upper left corner of the view to indicate if the character sequence matches or does not match the selected pattern definition.
7. If required, modify the regular expression according to your needs and then click Save to save your modifications.

   The pattern definition is modified accordingly in the pattern editor.