How to get the ASCII value of the first character of the a given string using the ASCII() function?

ASCII(string) is a MySQL built-in function that returns the ASCII value of the first character of a giving string. For example:

SELECT ASCII('dba.FYIcenter.com');
  -- +----------------------------+
  -- | ASCII('dba.FYIcenter.com') |
  -- +----------------------------+
  -- |                        100 |
  -- +----------------------------+

SELECT ASCII('O'), ASCII('©'), ASCII('😋');
  -- +------------+-------------+---------------+
  -- | ASCII('O') | ASCII('©')  | ASCII('😋')     |
  -- +------------+-------------+---------------+
  -- |         79 |         194 |           240 |
  -- +------------+-------------+---------------+

SELECT HEX('O'), HEX('©'), HEX('😋');
  -- +----------+-----------+-------------+
  -- | HEX('O') | HEX('©')  | HEX('😋')     |
  -- +----------+-----------+-------------+
  -- | 4F       | C2A9      | F09F988B    |
  -- +----------+-----------+-------------+

Reference information of the ASCII() function:

ASCII(str): num
  Returns the numeric value of the leftmost character of the string str.
  Returns 0 if str is the empty string. Returns NULL if str is NULL.
  ASCII() works for 8-bit characters.

Arguments, return value and availability:
  str: Required. The given string to return the ASCII value
    of the first characters for.
  num: Return value. The ASCII value of the first character.
  Available since MySQL 4.0.

Related MySQL functions:

• CHAR() - Building String from Byte Values

⇒ BIT_LENGTH() - Number of Bits in String

⇐ MySQL Functions on Character String Values

⇑ MySQL Functions on Character String Values

⇑⇑ MySQL Function References