Oracle 函數 之 wm_concat()

wm_concat()

把列轉換成一行一列顯示，使用wm_concat函數可以顯示在一行一列。

--1 建表

create table province_city
(
province varchar2(100),
city varchar2(100)
);

--2 插入數據

insert into province_city (province, city)values ('陝西', '西安');
insert into province_city (province, city)values ('陝西', '寶雞');
insert into province_city (province, city)values ('陝西', '漢中');
insert into province_city (province, city)values ('湖北', '武漢');
insert into province_city (province, city)values ('湖北', '宜昌');
insert into province_city (province, city)values ('湖北', '襄陽');

commit;

--查詢結果

select * from province_city;

select province,
       wm_concat(city || chr(10)),
       wm_concat(city || chr(13)),
       wm_concat(city || chr(9))
  from province_city
 group by province;

--里面的子信息會按照一行一列的方式進行排列。