1. ASCII 返回與指定的字符對應的十進制數; SQL> select ascii(A) A,ascii(a) a,ascii(0) zero,ascii( ) space from dual; A A ZERO SPACE --------- --------- --------- --------- 65 97 48 32 2. CHR 給出整數,返回對應的字符; SQL> select chr(54740) zhao,chr(65) chr65 from dual; ZH C -- - 趙 A 3. CONCAT 鏈接兩個字符串; SQL> select concat(010-,88888888)||轉23 高乾競電話 from dual; 高乾競電話 --------