Intellij IDEA: specify datasource for JPA validation

First thing you have to add data source into your IDE. You can do it in the tab "Database" usually on right side. You can import this data source from your code. You should make sure that you hit button refresh tables. IDEA will load tables and use them for validation. Then you have to inside your JPA facet setup this data source.

I finally found out how to do this.

The key is the "persistence" tool window. Apparently it is made available after you add the JPA facet, but is a separate tool window.

To open it : menu "view" -> Tool Windows -> Persistence

In this window you see your application with the different persistence related elements (I see persistence.xml, entityManagerFactory from Spring context, and myUnit which I don't know where it comes from.

Here you can right-click on any element and choose "Assign data source".

This opens a pop-up dialog with a small table containing you persistence elements on the left column and the data source assigned to it on the right column. You can assign a datasource from the "Database" window in there, so I picked the datasource I had configured for my MySQL DB and voilà, the validation errors went away.

But if I enter a wrong table or column name, I still get an error, which is pretty neat.