Useful character built-in functions : CHAR VARCHAR2 Functions « PL SQL Data Types « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. PL SQL Data Types
3. CHAR VARCHAR2 Functions

CHR and ASCII are opposites.

CHR(code) returns a character from the current character set identified by its binary equivalent.

ASCII (character) returns the binary equivalent of the character passed into the function.

SQL>
SQL> declare
  2      v_nr number;
  3      v_tx char(1);
  4  begin
  5      v_nr:=ascii('A');
  6      DBMS_OUTPUT.put_line(v_nr);
  7      v_tx:=chr(v_nr);
  8      DBMS_OUTPUT.put_line(v_tx);
  9  end;
 10  /
65
A

PL/SQL procedure successfully completed.