Syntax error when using concat function

Question

I created a field to display the whole route of several photos in a point layer in order to be able to visualize them on the map. I try to do so by using this expression:

concat('C:\Users\DIDAC\Documents\CONSULT\EIA OLIVERES CLARAMUNT\treball camp\fotos\IGN\',"file_name")

"file_name" being the name of every photo.

Here's the error message: "syntax error, unexpected Unknown_CHARACTER"

• csk: Are you using this expression in the Field Calculator, or typing it directly into the attribute table?

Answer 1

Backslash characters need to be escaped in qgis expression strings. Replace each backslash in the path with a double backslash '\'.

• csk: So would the final expression look like concat('C:\\Users\\DIDAC\\Documents\\...?
• ndawson: Correct. The \ character is used to begin other "special" characters, like a \n = newline character. To get an actual \ literal you need to use `\`. (This is the same rules as Python or SQL languages)