During one of my classes I got a question hot to make cascading dropdowns in InfoPath 2010 for SharePoint 2010, so here is a Visual How to:

First, you have to make lists that will hold lookup data. I made a list called KategorjaNapake which is a category list and I made TipNapake list which is a Subcategory list. I made a reference to a category list with a lookup column.

 

SubCategory list with a reference to Category list, made with a lookup column.

Columns in subcategory list:

Create columns in main list for data. First I made a column for entering text data and the second column I made was a lookup column to a category list.

 

Here are the columns I made for a main list...

Next, we will customize a SharePoint list form with InfoPath 2010...

Insert a new line in InfoPath Form

Insert a new dropdown field...

Here, just click OK, we have to go into dropdown field properties to get more choices.

If you want to display column name in SharePoint as TipNapake you have to change it here, so change field1 to name that you want to use.

To create new data source for this field, go to properties

Choose get choices from external data source and click Add.

Pick SharePoint library or list...

Pick List that you want to connect to...

Choose fields that you want to have in your data source. It is very important here to also pick the category field.

To create a cascading dropdowns, prepare yourself for a click fest. So click on the button next to Entries.

Click Filter data

Test the form in InfoPath...

Click the Quick Publish Button...

Test your form in SharePoint List....

 

voilà