SQL Server Essential Function in Daily Work

Make different value Varchar  to integer SQL SERVER Function

Example::
dbo.getFirstNumeric(P.ChallanNO)

function :: dbo.getFirstNumeric()

How to check for Is not Null And Is not Empty string in SQL server?

Ref:: https://stackoverflow.com/questions/8660203/how-to-check-for-is-not-null-and-is-not-empty-string-in-sql-server

WHERE NULLIF(your_column, '') IS NOT NULL