Sort Wrapper List by two values

Question

I need to sort Wrapper List by two values(Quantity and Price). The below code Sorts List only by Quantity.How to sort list by both Quantity and Price.

public Class SortByTwoValues implements Comparable
{
    public Decimal Quantity{get; set;}
    public Decimal Price{get; set;}
    public String ItemName{get;set;}

    public Integer compareTo(Object compareTo) 
    {
        SortByTwoValues compareToRec = (SortByTwoValues)compareTo;
        if (Quantity == compareToRec.Quantity) 
            return 0;
        if (Quantity > compareToRec.Quantity) 
            return 1;
        return -1;        
    }    
}

Thanks in advance

Answer 1

You have to pick which field takes priority and only when that field is the same consider the second field.

So assuming you want to sort by quantity first and price second:

public Integer compareTo(Object compareTo) {
    SortByTwoValues compareToRec = (SortByTwoValues)compareTo;
    if (Quantity > compareToRec.Quantity) {
        return 1;
    } else if (Quantity < compareToRec.Quantity) {
        return -1;
    } else {
        // First value the same, consider second value
        if (Price > compareToRec.Price) {
            return 1;
        } else if (Price < compareToRec.Price) {
            return -1;
        } else {
            return 0;
        }          
    }       
}  

Answer 2

Another, & simpler, way to sort on multiple fields in Apex is to write your data to a table used to store data temporarily & then simply retrieve the same data again in a list using SOQL & use the 'order by' clause to sort the way you want.

The temporary data in the table can then be deleted using the same list you retrieved. You will still have the list to work with.