How to intercept a string's SQL statement from multiple locations

How to intercept a string's SQL statement from multiple locations:

Know: Field a= ' F:photowinter leaves.jpg '

Requirements: Segment intercept each character [field a cannot be text type, otherwise error]

Workaround:

---Intercept the first left string of string a

Select Left (A,charindex ('/', A)-1)

Output Result: F:

---intercept the middle string

Select Left (Stuff (A,1,charindex ('/', a), '), charindex ('/', Stuff (A,1,charindex ('/', a), '))-1)

Output Result: Photo

---intercept the last string behind

Select reverse (reverse (a), charindex ('/', reverse (a))-1)

Output Result: Winter leaves.jpg

---Intercept the first caption of a string a

Select STUFF (a,1, 1, "")

Output result::p hotowinter leaves.jpg