RANK

RANK returns the integer value corresponding to a character or widechar.

x

Must have the attributes CHAR (1) NONVARYING or WCHAR (1) NONVARYING.

If x is character, RANK(x) is defined as index(collate(),x)-1, and RANK is the inverse of CHARVAL.

If xx is widechar, RANK(x) is equal to UNSPEC(y) where y is x stored in bigendian format.