Programming the Perl DBI

Grouping and Ordering Data

Often you’ll desire a little more control over how your selected data is retrieved. The two most common ways of organizing your data are to order the retrieved rows by one or more columns, or to group the retrieved rows and apply functions to the groups instead of to individual rows.

Perl is well-suited to these tasks within your program, but performing ordering and grouping via SQL will offload the task onto the database server and also will save you writing, or using, potentially suboptimal techniques for organizing the data. Therefore, generally, use SQL rather than your own application-level code.