I went about things a different way. I removed image filepaths from the Excel and inserted products only. I then renamed images to what appeared to be the nopCommerce style e.g. 0000123_product-seo-friendly-name.jpeg and generated thumbnail variants in 64, 75, 100, 415 1nd 550 px widths e.g. 0000123_product-seo-friendly-name_64.jpeg. These images are in the Picture data table using the above example that would be ID 123, and the relationship is mapped in the Product Picture Mapping Table but most don't work! Clearly I have a naming conflict, so, rechecking that for now rather than return to your most welcome suggestions.
Would I be right in thinking the IsNew value in Picture should be set to True?
I didn't when I bulk imported my pictures, I set isNew = 0 and had no issues. If you don't already have generated thumbnails then it should have no effect.
isNew is used in various places during inserting/updating images, but where you're concerned is it deletes existing thumbs when the frontend calls for the image url
check the GetPictureUrl method in PictureService.cs
I'm just not getting this at all. Let me update you on what I've most recently done.
1. Generated images named 0001234_0.jpeg where 123 is the corresponding Id in Picture
2. Upload images to wwwroot\images
3. Generated records to relate Picture.Id and Product.Id in Product_Picture_Mapping
4. Restarted site in IIS
5. Viewed site to find only the default "No Image" showing in all but the ones where my previously created thumbnails had worked
6. Checked in to admin and noted that a few show a x as missing image yet when I check the source code and I can see the image 0000260_tee-#1-eaglemuscles-lkntht_75.jpeg as requested is indeed in the images\thumbs folder, realised the # would cause a problem and so corrected (this came from the product name), it now works but most still show the default No Image.
7. I'm guessing this is down to something daft like spurious spaces in the SeoFilename so tomorrow I'll do some random cross checking and see what I can find.
Thanks no problems with SQL that is my strength. This is loaded on a Virtual Server, hosted on a physical server that I have so I have complete access to all at the backend.
It was spurious chars such as carriage returns within the string. Couldn't be seen viewing t he SQL table but affected the results insofar as world1-word2-word3 was in effect word1-word2-'char(10)'word3