SQL Server 2005:charindex starting from the end - sql

Question

I have a string 'some.file.name',I want to grab 'some.file'.
To do that,I need to find the last occurrence of '.' in a string.
My solution is :
declare #someStr varchar(20)
declare #reversedStr varchar(20)
declare #index int
set #someStr = '001.002.003'
set #reversedStr = reverse(#someStr)
set #index = len(#someStr) - charindex('.',#reversedStr)
select left(#someStr,#index)
Well,isn't it too complicated?I was just intented to using 'some.file' in a where-clause.
Anyone has a good idea?

Answer 1

What do you need to do with it?? Do you need to grab the characters after the last occurence of a given delimiter?
If so: reverse the string and search using the normal CHARINDEX:
declare #test varchar(100)
set #test = 'some.file.name'
declare #reversed varchar(100)
set #reversed = REVERSE(#test)
select
REVERSE(SUBSTRING(#reversed, CHARINDEX('.', #reversed)+1, 100))
You'll get back "some.file" - the characters up to the last "." in the original file name.
There's no "LASTCHARINDEX" or anything like that in SQL Server directly. What you might consider doing in SQL Server 2005 and up is great a .NET extension library and deploy it as an assembly into SQL Server - T-SQL is not very strong with string manipulation, whereas .NET really is.

Answer 2

A very simple way is:
SELECT
RIGHT(#str, CHARINDEX('.', REVERSE(#str)) - 1)

Answer 3

This will also work:
DECLARE
#test VARCHAR(100)
SET #test = 'some.file.name'
SELECT
LEFT(#test, LEN(#test) - CHARINDEX('.', REVERSE(#test)))

Answer 4

Take one ')'
declare #test varchar(100)
set #test = 'some.file.name'
select left(#test,charindex('.',#test)+charindex('.',#test)-1)

Answer 5

CREATE FUNCTION [dbo].[Instr] (
-------------------------------------------------------------------------------------------------
-- Name: [dbo].[Instr]
-- Purpose: Find The Nth Value Within A String
-------------------------------------------------------------------------------------------------
-- Revisions:
-- 25-FEB-2011 - HESSR - Initial Revision
-------------------------------------------------------------------------------------------------
-- Parameters:
-- 1) #in_FindString - NVARCHAR(MAX) - INPUT - Input Find String
-- 2) #in_String - NVARCHAR(MAX) - INPUT - Input String
-- 3) #in_StartPos - SMALLINT - INPUT - Position In The String To Start Looking From
-- (If Start Position Is Negative, Search Begins At The End Of The String)
-- (Negative 1 Starts At End Position 1, Negative 3 Starts At End Position Minus 2)
-- 4) #in_Nth - SMALLINT - INPUT - Nth Occurrence To Find The Location For
-------------------------------------------------------------------------------------------------
-- Returns: SMALLINT - Position Of String Segment (Not Found = 0)
-------------------------------------------------------------------------------------------------
#in_FindString NVARCHAR(MAX),
#in_String NVARCHAR(MAX),
#in_StartPos SMALLINT = NULL,
#in_Nth SMALLINT = NULL
)
RETURNS SMALLINT
AS
BEGIN
DECLARE #loc_FindString NVARCHAR(MAX);
DECLARE #loc_String NVARCHAR(MAX);
DECLARE #loc_Position SMALLINT;
DECLARE #loc_StartPos SMALLINT;
DECLARE #loc_Nth SMALLINT;
DECLARE #loc_Idx SMALLINT;
DECLARE #loc_FindLength SMALLINT;
DECLARE #loc_Length SMALLINT;
SET #loc_FindString = #in_FindString;
SET #loc_String = #in_String;
SET #loc_Nth = ISNULL(ABS(#in_Nth), 1);
SET #loc_FindLength = LEN(#loc_FindString+N'.') - 1;
SET #loc_Length = LEN(#loc_String+N'.') - 1;
SET #loc_StartPos = ISNULL(#in_StartPos, 1);
SET #loc_Idx = 0;
IF (#loc_StartPos = ABS(#loc_StartPos))
BEGIN
WHILE (#loc_Idx < #loc_Nth)
BEGIN
SET #loc_Position = CHARINDEX(#loc_FindString,#loc_String,#loc_StartPos);
IF (#loc_Position > 0)
SET #loc_StartPos = #loc_Position + #loc_FindLength
ELSE
SET #loc_Idx = #loc_Nth;
SET #loc_Idx = #loc_Idx + 1;
END;
END
ELSE
BEGIN
SET #loc_StartPos = ABS(#loc_StartPos);
SET #loc_FindString = REVERSE(#in_FindString);
SET #loc_String = REVERSE(#in_String);
WHILE (#loc_Idx < #loc_Nth)
BEGIN
SET #loc_Position = CHARINDEX(#loc_FindString,#loc_String,#loc_StartPos);
IF (#loc_Position > 0)
SET #loc_StartPos = #loc_Position + #loc_FindLength
ELSE
SET #loc_Idx = #loc_Nth;
SET #loc_Idx = #loc_Idx + 1;
END;
IF (#loc_Position > 0)
SET #loc_Position = #loc_Length - #loc_Position + (1 - #loc_FindLength) + 1;
END;
RETURN (#loc_Position);
END;
GO

Answer 6

Here is a shorter version
DECLARE #someStr varchar(20)
set #someStr = '001.002.003'
SELECT REVERSE(Substring(REVERSE(#someStr),CHARINDEX('.', REVERSE(#someStr))+1,20))