1.instr为字符查找函数
select instr('ab','a') from dual; --1
select instr('ab','c') from dual; --0
2.listagg 列转行
--aa/bb 代表列
select listagg('aa' || '%' || 'bb') within group (order by 'aa') from dual; -- aa%bb
3. distinct 去重函数
select distinct 'aa' from dual; -- aa
4.replace 替换
select replace(replace('ab ',chr(10),''),chr(13),'')) from dual; -- ab