How to use NULL or empty string in SQL

Question

I would like to know how to use NULL and an empty string at the same time in a WHERE clause in SQL Server. I need to find records that have either null values o

Answer 1

youe check null With IS NULL and string Empty With LEN(RTRIM(LTRIM(Column))) = 0 in

SELECT *
FROM AppInfra.Person
WHERE   LEN(RTRIM(LTRIM(NationalCode))) = 0 OR  NationalCode IS NULL