Julia Programming Projects

@orderby

Query also provides a sorting macro named @orderby. It takes a list of attributes upon which to apply the sorting. Similar to SQL, the order is ascending by default, but we can change that by using the descending function.

Given our previously defined products_info DataFrame, we can easily sort it as needed, for example, with the most expensive products first and then by product name:

julia> @from p in products_info begin 
           @orderby descending(p.price), p.produce 
           @select p 
           @collect DataFrame 
        end 

The snippet shows how to employ @orderby to sort the values in the source. Unsurprisingly, the resulting DataFrame will be properly sorted with the most expensive products on top:

All right, that was quite a detour! But now that we have knowledge ...