Sorry about the empty reply, my son keep pressing the mouse...

I used method 1 as you have told, double ((__)) and ASC. the error i
got is 'Access Violation at address 00404BBA...'

The reason i need the latest 30 days data is because the stock
information is not upto date (eg is not up today's date). some stock
data are 5 days old, 10 days and some 30 days old.

I use Delphi 7.

Need help, dont know about database.