regex - Extracting text before forward slash (/) in QGIS?

I have a database of motorway junctions which are named like this:

• M90 J8/A91/B996



• M90 J1/A90/A921/A985(T)


• M9 J1A

There is significant variability in the length of the strings but they all follow the same basic pattern of Motorway ID Junction Number / Link Road IDs

How do I extract everything before the first forward slash i.e. the Motorway ID and Junction Number?

I've been trying to use regex_substr based on other answers on here like this: regexp_substr( "NAME", '^(.+)/') but this extracts everything before the last forwardslash. How can I alter it to get the text before the first slash?

Answer

This turns out to be doable without using the regex_substr function. Instead the code

left( "Name", strpos( "Name" ,'/'))`

can be used instead. It works by identifying the string position of the first / and then extracting the text to the left of that position.

If anyone has any suggestions regarding regex_substr I'd still like to see them though.