Hi,
Please check very detailed explaination Adhoc Query
The maintain transaction for Ad Hoc query are SQ01, SQ02,SQ03. Using ad hoc query you can fetch data from various infotypes fields, that can be stand alone or combination of infotypes.
You would require technical help in case you need to create selection screen for the ad hoc or you want to access ad hoc query using a Z transaction ( this is one of the scenario there may be other scenarios where you need to abap developments)
Ad Hoc uses/supports 3 logical databases PNP,PCH,PAP ( employee data, org data , payroll data) PNPCE is the latest version of PNP, PNPCE supports concurrent employment model.
Thanks