I have 2 fields(LastName and FirstName), I want to return it as one field(name)

You can only concatenate the output of the query not the columns in the query itself.

@narasimham It isn't possible using the a!queryColumn but definitely it is doable and one of the several possible ways of doing it is, you could create a database view (which contains all the columns from the source table and an additional column that concats the first name and last name columns) and then create a cdt + data store entity that maps to the database view.

Once you run your query, you have a data subset. You can then use merge and apply to process the data subset one name at a time.

We do something similar in this code, concatenating two fields together with a dash.

with(
local!query: a!query(pagingInfo: topaginginfo(1, -1)),
local!ds: a!queryEntity(entity: cons!RC_REQUEST, query: local!query),
local!merge: merge(local!ds.data.tRequestAction, local!ds.data.tRequestCategory),
apply(fn!concat(_, "-", _), local!merge)
)