1.截取字符串

mysql

SUBSTRING_INDEX(SUBSTRING_INDEX(b.`ELEMENT_ALLPARENT_ID`,',',3),',',-1) AS deno

 

oracle

'402881e96274cd86016274cd86630000,8aaa87176415997a016421903b720034,402881e96275cee9016275d4fbdd000a'   截取，号后的32位

select substr('402881e96274cd86016274cd86630000,8aaa87176415997a016421903b720034,402881e96275cee9016275d4fbdd000a',

instr('402881e96274cd86016274cd86630000,8aaa87176415997a016421903b720034,402881e96275cee9016275d4fbdd000a',',',-1,1)+1,32

)from dual

 

instr(sourceString,destString,start,appearPosition).   instr（

'源字符串'

,

'目标字符串'

,

'开始位置'

,

'第几次出现'

）

返回目标字符串的位置   下标从1开始

SQL>

select

instr(

'yuechaotianyuechao'

,

'ao'

) position

from

dual;

 

 

POSITION

 

----------

 

6

 

从第7个字符开始搜索<br>

SQL>

select

instr(

'yuechaotianyuechao'

,

'ao'

, 7) position

from

dual;

 

 

POSITION

 

----------

 

17

 

substr(

string

, start_position, [ length ] )       substr(

'目标字符串'

,开始位置,长度)

     

substr(

'This is a test'

, 6, 2)     would

return

'is'

      

substr(

'This is a test'

, 6)     would

return

'is a test'

      

substr(

'TechOnTheNet'

, -3, 3)     would

return

'Net'