Using CHARINDEX in SQL Query

CHARINDEX returns a starting position of a string which helps developer to split a data based on th erequirement. Below is an example of CHARINDEX usage:

DECLARE @AMT Varchar(50) = '$50K - $70K'
SELECT REPLACE(SUBSTRING('$50K - $70K',charindex('$', '$50K - $70K')+1, charindex('K', @AMT)),'K','') AS MinRange
,REPLACE(SUBSTRING('$50K - $70K',charindex('-', '$50K - $70K')+3, charindex('K', @AMT)),'K','') As MaxRange
The output is:
----------------------------------
MinRange      MaxRange
-----------------------------------
50                   70
-----------------------------------