oracle sql 进行遍历查询

SELECT *

FROM (WITH temptest AS (SELECT LEVEL lv FROM DUAL connect BY LEVEL <= 10)

select lv,

cnt,

gdm,

substr(vals,

instr(t.vals, ‘,‘, 1, ts.lv) + 1,

instr(t.vals, ‘,‘, 1, ts.lv + 1) -

(instr(t.vals, ‘,‘, 1, ts.lv) + 1)) AS name

from (SELECT g.gdm,

‘,‘ || g.gdgr || ‘,‘ as vals,

(LENGTH(‘,‘ || g.gdgr) - LENGTH(REPLACE(gdgr, ‘,‘))) as cnt

FROM MYTEST.GD g) t

join temptest ts on ts.lv <= t.cnt

where gdm = ‘腾讯‘

)

原数据

主要是为了将以逗号存的数据以行的形式展现出来

思路是先获取到数据的长度，然后遍历的时候判断长度，并且，根据这个参数去截取到对应的值，不过效率的方面感觉不咋好