0x01 || 字符串拼接

  1. select 1||2||3 from dual;
  2. 运行结果: 123
  3. select 1||'2'||3 from dual;
  4. 运行结果: 123
  5. select 1||'a'||3 from dual;
  6. 运行结果: 1a3