From Jpaliowiki EN

Generally

JDesigner makes it possible to put a dynamic database queries.

SQL option is available on the tool menu as shown below:

To ask a query to the database, you need to add the connector to the database. Click on the "+" button and choose the connector that interests you. If you are already connected to the database you can write the query in a text field. To execute the query click on the icon yellow button or press Ctrl + Enter. The list of results will be written out in the window below. On the control bar is displayed query time and the number of rows displayed.