Oracle PL/SQL Programming, Third Edition

Name

ASCII

Synopsis

The ASCII function returns the NUMBER code that represents the specified character in the database character set. The specification of the ASCII function is:

FUNCTION ASCII (single_character IN VARCHAR2) RETURN NUMBER

where single_character is the character to be located in the collating sequence. Even though the function is named ASCII, it will return the code location in whatever the database character set is set to, such as EBCDIC Code Page 500 or 7-bit ASCII. Remember that the collating code for uppercase letters is different from that for lowercase letters. For example, in the 7-bit ASCII character set, ASCII (“a”) returns 97. ASCII (“A”) returns 65 because the uppercase letters come before the lowercase letters in the sequence.

If you pass more than one character in the parameter to ASCII, it returns the collating code for the first character and ignores the other characters. As a result, the following calls to ASCII all return the same value of 100:

ASCII ('defg')
ASCII ('d')
ASCII ('d_e_f_g')