How to get first character beside underscore for a given string - sql

Question

input:
string
'abc_def_ghk_lmn'
output:
dgl

Answer 1

You can try this (or even create a function):
DECLARE #str varchar(250) = 'abc_def_ghk_lmn'
DECLARE #result varchar(250)='';
WHILE(charindex('_',#str)!=0)
BEGIN
DECLARE #position int = charindex('_',#str)
SET #result += substring(#str,#position+1,1)
SET #str = substring(#str,#position+1,len(#str))
END
SELECT #result

Answer 2

You can use a recursive CTE:
IF OBJECT_ID('tempdb..#t') is not null drop table #t
SELECT * into #t from (values (N'abc_def_ghk_lmn'), (N'a_f_k_n'), (null), ('____'), ('asasas'), ('a_sasas'), ('asas_')) T(val);
;WITH CTE AS
(
SELECT
Cast(SUBSTRING(T.val, CHARINDEX('_',T.val,1) + 1, 1) as nvarchar(4000)) FC
,CHARINDEX('_', T.val, 1) CI
,val
,0 [level]
from #t T
where CHARINDEX('_', T.val, 1) > 0
union all
SELECT
Cast(T.FC + SUBSTRING(T.val, CHARINDEX('_',T.val,T.CI+1) + 1, 1) as nvarchar(4000)) FC
,CHARINDEX('_', T.val, T.CI+1) CI
,val
,t.[level] + 1
from CTE T
where CHARINDEX('_',T.val,T.CI+1) > 0
)
, Res AS
(
SELECT
*
,ROW_NUMBER() OVER (Partition by val order by [level] desc) RN
from CTE
)
SELECT * from Res where RN = 1

Answer 3

This uses Jeff Moden's DelimitedSplit8K Function. Firstly because i don't know what version of SQL Server you are using, and secondly, the inbuilt function STRING_SPLIT (available in SQL Server 2016 onwards) doesn't include an Item Number value (thus how does one exclude the first result?):
SELECT (SELECT LEFT(Item, 1)
FROM DelimitedSplit8K ('abc_def_ghk_lmn','_') DS
WHERE DS.ItemNumber > 1
FOR XML PATH(''));
Edit:
Example with a dataset:
WITH VTE AS(
SELECT *
FROM (VALUES ('asdgsad_sdfh_sadfh'),('_ashdf+ashd'),('jsda_sdkhfsdjf_654_asdfkhasd_567465413_kasbgdjkasdj')) V(S))
SELECT (SELECT LEFT(Item, 1)
FROM DelimitedSplit8K (S,'_') DS
WHERE DS.ItemNumber > 1
FOR XML PATH('')) AS FirstCharacters
FROM VTE;

Answer 4

Try this:
DECLARE #String VARCHAR(50)= 'abc_def_ghk_lmn',#Result VARCHAR(10)=''
WHILE CHARINDEX('_',#String)>0
BEGIN
SELECT #Result=#Result + SUBSTRING(#String,CHARINDEX('_',#String)+1,1)
SELECT #String=RIGHT(#String,LEN(#String)- CHARINDEX('_',#String))
END
SELECT #Result FinalResult
OUTPUT:
FinalResult
dgl

Answer 5

Please try this -...Always use SET BASED Approach
SOLUTION
DECLARE #x AS XML=''
DECLARE # AS VARCHAR(1000) = 'abc_def_ghk_lmn_'
SET #x = CAST('<A>'+ REPLACE(#,'_','</A><A>')+ '</A>' AS XML)
;WITH CTE AS
(
SELECT t.value('.', 'VARCHAR(10)') Value FROM #x.nodes('/A') AS x(t)
)
,CTE1 AS
(
SELECT * , ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) rnk FROM CTE
)
,CTE2 AS
(
SELECT SUBSTRING(Value,1,1) v , rnk FROM CTE1
)
SELECT CASE WHEN LEFT(#,1) <> '_' THEN MAX(SUBSTRING(u,2,LEN(u))) ELSE MAX(u) END finalstr from (
SELECT
(
SELECT '' + v
FROM CTE2 a
FOR XML PATH('')
)u
FROM CTE2 )x
OUTPUT
finalstr
---------------
dgl
(1 row affected)

Answer 6

Try this below
DECLARE #str TAble(String varchar(250))
INSERT INTO #str
SELECT 'abc_def_ghk_lmn_opq_rst_uvw_xyz'
SELECT STUFF((SELECT ''+LEFT(String,1) FROM
(
SELECT Split.a.value('.','Varchar(1000)') As String,
ROW_NUMBER()OVER(ORDER BY (SELECT 1)) AS Id FROM
(
SELECT CASt('<S>'+REPLACE(String,'_','</S><S>')+'</S>' AS XML )AS String
FROM #str
)as A
CROSS APPLY String.nodes ('S') AS Split(a)
)dt
WHERE dt.Id <>1
FOR XML PATH ('')),1,0,'') AS ExpectedColumn
Result
ExpectedColumn
--------------
dglorux

Answer 7

Use LEFT to get the left part and INSTR to find underscore and finally get your string:
SELECT LEFT(FIELD_1, CHARINDEX('_', FIELD_1) - 2) AS [ANY_ALIAS]
FROM TABLE_1;
EDIT: Now is MSSQL... ;D