# Declaring a User-Defined Function in a specific database

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

The regular expression function is not built into all different database environments. If you want to use Talend Studio to analyze columns against regular expressions in databases that do not natively support regular expressions, you can:

Either:

1. Install the relevant regular expressions libraries on the database.
2. Define a query template for the database.

Or:

1. Execute the column analysis using the Java engine. In this case, the system will use the Java regular expressions to analyze the specified column(s) and not SQL regular expressions. For more information on the Java engine, see [Using the Java or the SQL engine](https://help.qlik.com/talend/en-US/studio-user-guide/8.0/using-java-or-sql-engine).