SQL Server character processing (LastIndexOf usage), STUFF, CHARINDEX, REVERSE, LEN

DECLARE @s VARCHAR (100)
SET @s= ' r1-1-1 ' gets the number after the last "-"
SelectREVERSE(@s) return value: 1-1-1R reverses the character. SelectLEN(@s) return value: 6 Get length SelectCHARINDEX(‘-‘,REVERSE(@s)) Return value: 2--Gets the position of the first occurrence of a string, and returns 0 Select if no character is changedSTUFF(@s,1,LEN(@s)-CHARINDEX(‘-‘,REVERSE(@s)) +1, ') return value: 1
STUFFFunctionSTUFF (expression, start, length, Relacechar)                                         expression: A string to be processed                                    Start : Starting location (by the way, it's a reminder that SQL Server starts with 1, not 0)
                                             Length: Number of characters to replace                                    Relacechar: Replace selected characters with XXX

Processing of SQL Server characters (LastIndexOf usage), STUFF, CHARINDEX, REVERSE, LEN