如何在Oracle SQL中的第一个连字符之后和第三个连字符之前提取数据

Question

I have a requirement, Where i have a column value like STEP_D1_DEVTS_MN_PQ_LS

I want the value after 1st underscore and before 3rd underscore and then get the replace the underscore with hypen like below

D1-DEVTS .

Can some one please help me out here ?

I tried SUBSTR and INSTR that did not help me out.

Answer 1

Another is to use SUBSTR + INSTR (along with REPLACE , of course):

SQL> with test (col) as
  2    (select 'STEP_D1_DEVTS_MN_PQ_LS' from dual)
  3  select
  4    replace(substr(col,
  5                   instr(col, '_', 1, 1) + 1,                          --> start after the 1st underscore
  6                   instr(col, '_', 1, 3) - instr(col, '_', 1, 1) - 1   --> take everything that's between 1st and 3rd underscore
  7                  ), '_', '-') result                                  --> replace _ with -
  8  from test;

RESULT
--------------------
D1-DEVTS

SQL>

Answer 2

One option would be using concurrent regexp_substr expressions with a replace

with t(str) as
(
 select 'STEP_D1_DEVTS_MN_PQ_LS' from dual   
)    
select replace(regexp_substr(str,'[^_]+[_]',1,2)||regexp_substr(str,'[^_]+',1,3),'_','-') 
    as "Result String"
  from t;

Result String
-------------
D1-DEVTS