LASTPOS (Last Position)
The LASTPOS function returns the position of the last occurrence of one string, needle, in another, haystack.
LASTPOS returns 0 if needle is the null string or is not
found. By default the search starts at the last character of haystack and scans
backward. You can override this by specifying start, the point at which the
backward scan starts. start must be a positive whole number and defaults to
LENGTH(haystack) if larger than that value or omitted. See also the POS function,
POS (Position).
Examples
LASTPOS(' ','abc def ghi') -> 8
LASTPOS(' ','abcdefghi') -> 0
LASTPOS('xy','efgxyz') -> 4
LASTPOS(' ','abc def ghi',7) -> 4