kwiknip

+1 BIG TIME for data merge.  Frankly, without it, there is really no reason to move to an affinity publisher platform from my current workflow.  
To date, Designer and Photo have served my needs very well.  I started with Designer and after a few weeks use there, Photo was happily purchased.  If Publisher debuts without data merge, I will just have to wait patiently until the feature is added; Publisher would will not be an automatic purchase.
I truly believe that you will be shooting yourself in your foot if you launch a software application targeting professionals and advanced hobbyists/amateurs without a top-notch, innovative, and user-friendly data merge capability.  In the circles I create, this feature alone could set you apart and drive demand from hundreds of users to your software.
 
Best of luck with your project.
Cheers

Another vote for Data Merge. While InDesign's implementation might not be the best, it is a very useful feature. I've used ID's data merge on various projects. Being able to link to images is great and automatically updating a document with a new merge file is a real time saver.

@gregoiredierendonck, @Sponka, @debiant, @Josh Mills, @lights95 , @BoloGauranga, @TomJG  @am2008, @J. One, @ilocho and anyone else I have missed (sorry)
Welcome to the Serif Affinity forums
I have pinned this popular post to the top of the forum for others to find more easily. I cannot say if this will be implemented anytime soon, but clearly it would be desirable to you and others.

Hello, one more vote for "data merge" tool like in InDesign. I use this function mostly for designing business cards and small catalogs, labels for boxes etc ... Everything, that have same desing and elements, that change always on same places and can be read frome some kind of database.

I use the data merge tool daily to create QR-codes in a batch or load data into a pdf. I think this is not present in the beta build?

With InDesign I can place a lot of file types, including Word documents. InDesign doesn't natively support bidirectional synchronisation of linked Word documents (the WordsFlow software/plugin takes care of that), but I'd love to see this as a native feature in APu. It makes it a lot easier to work with copywriters as they can focus on the text using Word, while the designer simply links the contents in 'their' document. Any changes in the Word file will get auto-updated in APu (ideally also vice versa). InDesign also has a very simple, yet effective, data merge function. This is something I use a lot and it would be sorely missed if APu won't get it. Support of CSV-files for data sources would suffice IMO. Table styles are too hard to find and nearly impossible to understand, which makes using them a real PITA. This should get some more love & attention IMO. Lastly, I seem to unable to find where Object styles are hidden, if they are available at all. These are incredible time savers that are immensely important for continuity.

IMHO; Adding AppleScript capabilities would truly be a great asset & allow users to eventually automate task for entire workflows.  Even better to have AppleScripts communicate across the entire Affinity Suite (use it to automatically create a photo collage in AP--then apply preset vector graphics or type fx in AD--then combine the layouts in APub with variable data).  I can totally visualize what a huge time saving feature this could be, and best of all Apple hasn't abandoned AppleScript for developers.