If you're interested in Win32 apps, and you're using Crystal 7-8.5,
the help file (UCrpeDS.hlp, specifically), should provide enough
examples. Essentially, for every table in your report, you
associate a CrpeDS component to the Delphi TDataset, then tell the
report to use those instead of a direct database connection. FWIW,
I get much better performance if I do this than allowing Crystal to
go directly to the database, especially if I massage the data into
a single TQuery/TADOQuery/TOracleDataSet.
I have not done any .NET stuff, or Crystal newer than 8.5 so I
can't really help you if you're stuck on ECO.