How to create dynamic ui from database

Can you be more precise with your question and requirement? It's not clear what type of data you have and what type of UI you are trying to build. 
Also, have you gone through the interface lessons of Appian?

Yes, some additional details on your use case would be good for us to best assist.

I have one survey application where the process owners can define the questions, field types (text, paragraph, integer, radio buttons etc) and optional answers (for dropdowns or radio buttons).  These settings are stored to the database.  When the survey is displayed to the user, we query the DB for the list of questions, based on their type different questions are loaded by having one interface for each field/question type of text, integer, paragraph, dropdown, multi-dropdown, etc etc.

The nested if()s aren't optimal but it works great :)

Are you stuck on pre-22.1?  That looks like a perfect candidate for conversion to a!match() when you can get to it.

Yep, 21.1.  We will be updating shortly however

I have 2 DataTable consider Table1 and Table2.

if i select Table1 it should create an interface called Sample1 for table1  and

if i select table2, Sample1 change dynamically and have the fields of table2

am not sure is it possible in appian?

you would just build a separate interface to suit your needs for each of those tables individually.  then you could design a "parent" interface which just contains the selector, and depending on the selection, call either of the existing specific interfaces as children.  This is a very standard interface design practice - have you completed the Appian interface design training sessions, by chance?

can you send me that training link