using str_to_date with seperate fields

[Peter van Mierlo]

Hi,

Within a MySql table a date will be stored into 3 different fields, called
buyDay, buyMonth, buyYear al of the type VARCHAR.

Now the customer would like to create a selectiong using a dateTime picker (used in a Delphi) for selecting a START and END date and build the query.
This query will be stored into the application. If did try something like:

Select str_to_date(buyDay+"-"+buyMonth+"-"+buyYear) as buyDate, * from ticket_sales where buyDate >= :DateStart and buyDate <=DateEnd

I needs to be a european date format dd-mm-yyyy.

How can i realize this or how can i "create" a buyDate using
Str_To_Date function

Thanks