Word for someone who prepares reports
Solution 1:
The field in which someone runs database queries is data analysis:
Analysis of data is a process of inspecting, cleaning, transforming, and modeling data with the goal of highlighting useful information, suggesting conclusions, and supporting decision making. Data analysis has multiple facets and approaches, encompassing diverse techniques under a variety of names, in different business, science, and social science domains.
A person in such a field is a data analyst. That is, they figure out which data is relevant and then run queries.
Solution 2:
The official EU word is rapporteur, which possibly confirms that there is a problem with this word. However, as a report is normally the end result of a process of research or analysis, I would say researcher or analyst depending on usage in the context.