>I am using Delphi XE6 and Firedac and my query is similar to 
>
>SELECT A.NAME, 'HTTP://WWW.XYZ.COM?URN=' || A.URN || '&ACTION=' || A.ACTIONFIELD
>FROM MYTABLE
>
>the problem I have is that the returned result doesn't include the &ACTION so it looks like HTTP://WWW.XYZ.COM?URN=1234=myaction
>
>I have tried various ways of escaping the & but no joy.

As Mark said, this is not Firebird related, and hence off-topic for this list.

A quick search on the Internet, gives this likely answer from DA-SOFT Technologies Support Team (however, an answer for AnyDAC, not FireDAC):

"1) AnyDAC recognizes '&' and '!' as macros marker. To disable macro processing set ResourceOptions.MacroCreate and MacroExpand to False. More about that:
www.da-soft.com/anydac/docu/Preprocessing_Command_Text.html

2) Still the best is to use parameters instead of literals."

HTH,
Set