Oracle 高级函数

wm_concat(字段) 内容列显示 变成行显示
substr(字段，number)
trunc(字段，number)number为空截取全部小数，不四舍五入，限定小数的位数
instr(‘abc’,’a’);表示在abc中查找有没有a这个字符。

select ceil(9.5) from dual union   select floor(9.5) from dual;结果为：9      10--1select year,wm_concat(amount) from test  group by  year   结果为：    ——————————————————————    |year | ---          |    |2015 |  1.1,1.2,1.3 |    |2016 |  1.1,1.2,1.3 |      —————————————————————— --2    select year,substr(wm_concat(amount),1,3) m1,substr(wm_concat(amount),-7,3) m1,substr(wm_concat(amount),-3) m1   from test    group by  year       ————————————————————————  |year |  m1 | m2 |  m3 |  |2015 | 1.1 |1.2 | 1.3 |  |2016 | 1.1 |1.2 | 1.3 |    ————————————————————————