ASCIISTR takes as its argument a string, or an expression that resolves to a string, in any character set and returns an ASCII version of the string in the database character set. Non-ASCII characters are converted to the form
xxxx represents a UTF-16 code unit.
The following example returns the ASCII string equivalent of the text string "
SELECT ASCIISTR('ABÄCDE') FROM DUAL; ASCIISTR(' ---------- AB\00C4CDE