How to make a custom report builder?

Question

.NET

There is a client-server application. Plus a DB server (MS SQL). We will assume that everything is implemented in C#. Users are constantly asked to make some kind of reports. Directly in the program we make a button. We write assembly. The Word opens at the user and everything is entered there. Or a pre-made template arrives at the client's place and is filled. Sometimes we make a template in a crystal report. And the assembly transfers everything there. And at least upload it to pdf.
The question is how to give it all to users so that they make reports for themselves. I want them to be able to open a window right in the program. There would be a graphic editor with gadgets, as in a Word. On the side would be a tree of objects and attributes. Some operators for conditions. So that they don't need to know tables and sql. So that they can choose where and how to upload. And open and edit previously made reports.
Maybe there are some articles, books, a set of rules for such things? Any libraries that could help? Ready-made technology or implementation of a layer (something like a translator for SQL) between the user and the DBMS? Roughly speaking, I want to make mini crystal reports inside the program and so that a user without in-depth knowledge can use it.
PS: Excuse me for not being brief and without professional terminology. I am not a programmer by profession. So I write all sorts of little things to simplify the work of users. Or something ready to correct little by little. Just an idea was born. Looks great in the head. I just would like to understand how this is done. And is it done at all. Suddenly you say that it is not an option and this is a unique solution every time. And everything needs to be written from scratch. I'll calm down then. And I'll be happy to read anything you throw away. There is no need to reinvent the wheel.

Answer 1

They did several options: tags were replaced in RTF, there was an own editor similar to Excell made on StingrayGrid with custom formulas that select data. Everything seems to be simple and convenient, but it was still easier for users to pay than to make up. Therefore, it is better to make tools for yourself (now we use XSLT + XSL FO in PDF simply and beautifully) and reduce costs than to try to shift your work to others.