我的AMPScript LookUp函数有什么问题？

Question

Long time lurker, first time poster. I really appreciate any help!

I am trying to pull Subject Lines from a separate data extension than our sendable data extension. There are different subject lines stored here, and they vary by each record.

I'm using the LookUp() function, but for some reason it only works if I choose the data extension that I am supposed to be looking up for a send preview in Exacttarget.

So let's say my sendable data extension is called "SendableDE" (creative, right?) and the data extension that I am looking up is "DEWithSubjectLines". For example, I have

%%[SET @subjectLine =     Lookup("DEWithSubjectLines","SUBJ_LINE","SUB_KEY",_subscriberkey)]%% Returns:     %%=v(@subjectLine)=%% 

So, if I choose "SendableDE" when I do a Send Preview in ET, the function returns nothing.

But, if I choose "DEWithSubjectLines" when I do a send preview, the dynamic subject line is returned as intended and changes as I click through the different records. But why would it only work with that data extension? That pretty much defeats the purpose of the LookUp function.

I must be missing something conceptually here. Any thoughts? Thanks!

Answer 1

Welcome, Jake. You'll get a lot more eyes on your SFMC questions over at salesforce.stackexchange.com , specifically with the Marketing-Cloud and AMPScript tags.

The _subscriberkey personalization string isn't assigned until an email is sent to an address for the first time. Perhaps you're previewing against an email address that has never been sent an email from the account? Unless your business requirements dictate otherwise, it might be a good idea to use the emailaddr personalization string instead:

%%[

var @subjectLine
set @subjectLine = Lookup("DEWithSubjectLines","SUBJ_LINE","SUB_KEY",emailaddr)

]%%
<br>@subjectLine:%%=v(@subjectLine)=%%