Oracle string interception from backward forward interception method ____oracle

Oracle string interception from backward forward method

The format of the Instr:instr method is

INSTR (source string, target string, start position, match ordinal)

The default lookup order is left to right. When the starting position is a negative number, start looking from the right.

SUBSTR: Fetching substring string

SUBSTR (source string, starting position, number of bits to take)

From start position, take "how many"

Select ' za01x-00000 ' as Item_code
, InStr (' za01x-00000 ', ' -00000 ', -1,1) as position
, substr (' za01x-00000 ', InStr (' za01x-00000 ', ' -00000 ', -1,1), Length (' za01x-00000 ')) as result
From dual
;

--
Item_code POSITION Result
za01x-00000 6-00000
--
Select substr (' za01x-00000 ', -6) as result
From dual
;
--
Result
-00000
--

--to intercept the '-00000 ' string in item CODE

--Liu Yihe