Extracting part of string from field in QGIS Field Calculator?

Question

I want to create a new field in my attribute table. My goal: returning all digits between the / and _ characters of the field named "location" by applying the next expression:
regexp_substr( "Text", '/(d*)_' )
based on this working example: Obtaining specific part of string from field in QGIS attribute table?
However, the expression does not give the desired result in my case:

Does anyone know any way to modify/accommodate the expression?

ahmadhanb · Accepted Answer

Since the number of characters is same, you can use substr() function on a new field as in the following expression:
substr( "Location" ,17,6)

In the above example I used Path instead of Location

asongtoruin · Answer

A couple of issues - first, you don't need to escape (i.e. put a backslash before) the underscore. Your pattern also suggests that the digits follow immediately after a forward slash - which they do not, there is a w between them in each of your examples. If this is consistently a w, you could do:

regexp_substr( "location", '/w(d*)_' )

but in reality, if you're just trying to get every number before the underscore, you'd be sufficient with:

regexp_substr( "location", '(d*)_' )

As can be seen here:

user168488 · Answer

substr("location",16,(length("location")-1))

or
substr(substr("location",17,14),1,6)

that will return "W48535"

Extracting part of string from field in QGIS Field Calculator?

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