Merge two Reporting Services datasets into one

Question

I have two datasets from two different databases in my report. And the datasets have the same columns. How can i merge these datasets into one Dataset

I need some thing like this,

SELECT A,B,C FROM DATASET1
UNION
SELECT A,B,C FROM DATASET2

Answer 1

AFAIK, there is no equivalent in SSRS of creating a UNION from datasets coming from linked servers. Other similar questions get similar responses (e.g. this one).

Some workarounds could include using LookupSet, creating complex tablixes, and simply faking the union by having two identical tablixes below eachother, the second one not having any headers. Other than that you'll just have to union on the data-side itself, and not in SSRS.