Lookup Blob Field Type

m227 · Post by **m227** » Wed 09 Feb 2011 21:18

Dear Friends,

Is there any possibility to make Blob type field to be lookup or calculated?
I get message that such field type cannot be lookup or calculated but it comes form DB delphi unit.

Is there any way to override such behavior? I am aware that storage of BLOB fields is outside memory area of dataset records but find no excuse to be able to fetch it locally with OnCalculate (read only).

It would be convenient to make TBlob (graphic) field as calculated to fetch data to such field from local folder (pictures) instead to read huge amount of BLOB data from remote server.

Michal.

AndreyZ · Post by **AndreyZ** » Wed 16 Feb 2011 08:45

Hello,

You cannot use Blob fields as calculated or lookup fields. Maybe it will be appropriate for you to use the TVirtualTable component to store pictures in memory. If you don't want to store pictures in memory, the only solution is to load these pictures when they are needed.