Hi there, can you advise me if there's an option when data merging into InDesign to control the 'case' of text. Ie chose between Sentance Case, lowercase and so on.
If the fields on the document marked for merging are styled as per the need it should work fine after merge, but if you are asking that you would want to control this aspect during the merge, then i suppose it is not possible
One of the keys to a successful data merge is a clean and correct data file. (GIGO—garbage in garbage out) Correct the case in data file prior to merging and you should be good to go. Note that InDesign can change the display of text to All Caps or SmallCaps via a paragraph or character style, but sentence case and lowercase should be defined in the data file.
This cannot be achieved during the merge in InDesign directly. Still there are tools to do that like with MyDataMerge for macOS (a tool to make InDesigns data merge a lot more easy and comfortable).
You can control case of merged text per placeholder and also based on conditions just with a few clicks.
Its easy to start with but also complex in depth - ask in their support forum if you need support they answer pretty fast.
And they have a forever free version with some limitations which should be enough to try it. Check https://mydatamerge.com
I ran into this issue as well when trying to merge addresses for envelopes. Even though I had the text formatted in all caps in the .svg file as well as the data fields in my InDesign document, it still was importing as sentence case. I realized that a quick 'Find and Replace' search in Indesign quickly reformatted everything into all caps for me. A quick work around I wanted to share!
Sorry, I meant .csv file, not .svg!