padawan_linuxero,

You might want to try firing up the query tool for your database to manually execute your SQL query. This allows you to half-split the problem into an SQL problem, rather than an SQL + Perl + DBI problem.

Granted, it might not especially effective for this particular problem, but in general, it is a very useful and powerful means of troubleshooting as it allows you to tweak a query to your heart's content prior to embedding it into your code. Once you are confident that your query performs as intended, you can proceed to the next coding phase, confident that your SQL is functioning correctly.

For example, when I use PostgreSQL, I'll use the pgAdmin Query tool. If it's MSSQL Server, I'll use the MSSQL Query Analyzer. Once my query works perfectly there, It's just a cut-n-paste into my Perl code.

Unfortunately, I don't know of the name of the name of the query tool for DBF databases, so you're on your own there...