: Johan BRAUN
Then import all the wr7 document into new object fields and clear the
old picture or blob fields you got in your current database.
There are many possible ways and everyone can chose of course what’s best.
I personally would not recommend this approach.
Keep your old documents in blob fields. Don’t touch them, except they are created with 4D Write Versions older than 2004 or they contain pictures in Mac PICT (QuickDraw) Format.
Then, and only then, create a method running with 4D v17 or v16 in 32 bit mode and loop through all documents, convert pict to PNG or JPG and save the documents, to get them in latest 4D Write Format.
When an existing document is to be opened, you check if your object field is empty. Then use the old blob field and just open the document with 4D Write Pro.
If the user modifies and save, save it in the object field and empty the blob field.
This goes super fast (no need to export/import or run migration loop) and allows a step by step approach. And, if you make a mistake/error, you don’t destroy existing documents. And if we made an error in the document migration or we improve that with newer versions (and happened with 4D v18), you benefit from that.