Upload files and link them to resources

Northwind comes with images: a photo per employee, an icon per category. Uploaded files are stored content-addressed — the file's URL is derived from the SHA-1 hash of its\n content, under {base}uploads/. The same bytes always land at the same URL, which is what makes file references stable enough to bake into import mappings.

Linking files to resources

A file becomes part of the graph the moment something points at it. The category mapping from the Data stage does exactly that — the CSV carries each image's hash\n in its pictureHash column, and the mapping mints the upload URL from it:

?category foaf:depiction ?picture .\n...\nBIND(uri(concat(str($base), \"uploads/\", encode_for_uri(?pictureHash))) AS ?picture)

Source: categories/categories.rq

The employee mapping does the same with a photoHash column, linking the portrait with foaf:img, the predicate for an image of a person, while\n foaf:depiction is the looser depicts relation used for the category art.

\n \n \n

Click the Create dropdown at the bottom of the page and select File. Choose the file, give it a title, and save. The\n Upload file guide walks through the form in detail.

ldh add file \\\n    --title \"Nancy Davolio\" \\\n    --file employees/nancy.jpg \\\n    --content-type \"image/jpeg\" \\\n    \"$LDH_BASE\"

ldh add file prints the content-addressed URL of the upload ({base}uploads/{sha1}) as its only output, so it can be captured into a variable and referenced from imports or content.\n --content-type is optional — the media type is detected from the file when it is omitted.

What you now see

Category and employee documents now render with their images — foaf:depiction and foaf:img are picked up by the default layout, no template work required.

\n $\"An$ \n

How this works

Hierarchical URIs — the content-addressed uploads/{sha1sum} namespace in the dataset structure
Upload file — the upload form and the CLI command, step by step

Next: Insight